(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "The clay resources and the ceramic industry of California"

RBMHHB 




THE CLAY RESOURCES AND 

THE CERAMIC INDUSTRY 

OF CALIFORNIA 



BY 

WALDEMAR FENN DIETRICH 



BULLETIN No, 99 




ISSUED BY THE 

CALIFORNIA STATE MINING BUREi^n 

FERRY BUiLDLNG. SAN FRANCISCO 






1928 



l tfUlJMHW W W fW^a**^V V W<y W aJ»kVW*^&rtr'jy!b«VtnPttr 




THE LIBRARY 

OF 

THE UNIVERSITY 

OF CALIFORNIA 

DAVIS 




Photo No 1. Russ Building. San Francisoo, faced with architectural terra cotta 

throu^lTthron^\'''' 'f \?'" '"""' °' Gladding. McBean & Co. (Photo supplied 
tniougii the courtesy of the company.) 



54979 



STATE OF CALIFORNIA 

DEPARTMENT OF NATl RAL RESOURCES 

FRED G. STEVENOT, I)ir.-.t..r 

DIVISION OF MINES AND MINING 

FERRY BUILWNG, SAN FRANCISCO 
LLOYD L. ROOT State Mineralogist 

San Francisco] BULLETIN No. 99 [January, 1928 



The Clay Resources and the 

Ceramic Industry of 

Gahfornia 



By 
WALDEMAR FENN DIETRICH 

Associate Professor of Mining Engineer- 
ing, Stanford University 



CALIFORNIA STATE PRINTING OFFICE 
SACRAMENTO, 192 8 



LIBRARY 

UNIVERSliY OF CALIFORNIA 
DAVIS 



CONTENTS. 



Page 

Letter of transmittal 10 

Chapter I, Introduction 11 

Methods of investigation 12 

Previous work 12 

Acknowledgments 13 

General references 13 

Chapter II, Summary of the ceramic industry of California 15 

Introduction 15 

Definition of clay 15 

Kaolin 15 

China clay 15 

Ball clay 15 

Fireclay 15 

Pace brick clay 15 

Common brick clay 15 

Slip clay 15 

Clay preparation 15 

Manufacturing processes Ifi 

Shaping 16 

Drying 17 

Firing 17 

Glazing 17 

Clay deposits of California 17 

Mining methods 20 

Ceramic plants 21 

Manufacturing methods in California plants 26 

Common brick 26 

Hollow brick 26 

Face brick 26 

Sewer pipe 26 

" ^ Drain tile 26 

Terra cotta 26 

Conduits 27 

• Roofing tile 27 

Flue lining 28 

-Floor tile 28 

—~Wall and fireplace tile 28 

Refractories 29 

Tableware 30 

Kitchen w-are and stoneware 30 

Art pottery 30 

Red earthenware 30 

Sanitary ware 30 

Electrical insulators 30 

Thermal insulators 30 

Statistics 31 

.iw^— ' Brick and hollow tile 31 

Pottery clay 31 

Total annual value of clay products in California compared to the total 

for the United States 35 

Chaiiter III, Clay deposits and ceramic plants by counties 38 

Alameda County 38 

Amador County 49 

Butte County 64 

Calaveras County 67 

Colusa County 70 

Contra Costa County "1 

Del Norte County 77 

Fresno County 77 

Glenn Countv 79 

Humboldt County 79 

Imperial County 83 

Inyo County 87 

Kern County 88 

Kings County 90 

Lake County 91 

Lassen County 92 

Los Angeles County 92 

Madera County 123 

Marin County 123 

Mendocino County 126 

Merced County 127 

Monterey County 129 

Napa County 132 

Nevada County '. 135 

Orange County 139 

Placer County ; 146 

Riverside County 161 

Sacramento Countv 182 

San Benito County 190 



9^*^11 



b CONTENTS 

Page 

San Bernardino County 193 

San Diego County 19S 

San Francisco County 206 

San Joaquin County 207 

San Luis Obispo County 212 

San Mateo County 215 

Santa Barbara County 217 

Santa Clara County 219 

Santa Cruz County 222 

Shasta County 222 

Siskiyou Countv 224 

Solano County 225 

Sonoma County 225 

Stanislaus County 228 

Sutter County 230 

Tehama County 230 

Tulare County 231 

Ventura County 233 

Yolo County 234 

Yuba County 235 

Chapter IV, Clay tests and their interpretation and the classification of clays 237 

Field tests 237 

Laboratory tests 238 

Preparation of samples 238 

Test pieces 239 

Drying 239 

Plastic and drying properties 239 

Plasticity 239 

Water of plasticity 239 

Shrinkage water 240 

Pore \vater 240 

Shrinkage 240 

Dry transverse strength 240 

Bonding strength 241 

Fineness 241 

Firing properties 242 

Firing treatment 242 

Pyrometric control 243 

Firing shrinkage 245 

Absorption 245 

Apparent porosity 245 

Apparent specific gravity 245 

Apparent density 24(J 

True specific gravity 246 

Softening i^oint 246 

■ Texture, structure and hardness 248 

Color 248 

Ridgway color standards 249 

Munsell color standards 250 

Ridgway vs. Munsell 250 

Color classification of clays 251 

Chemical analysis 252 

Classification of clays 253 

Chapter V, Results of laboratory tests 257 

I. White- or cream-burning non-calcareous clays 257 

A. Open-burning 257 

1. Low strength 257 

2. Medium to high strength 264 

B. Dense-burning between cones 10 and 15 272 

3. Generally refractory 272 

C. Dense-burning between cones 5 and 10 273 

4. Generally refractory 273 

II. Buff-burning clays 277 

A. Refractory clays 277 

a. Open-burning 277 

5. Low strength 277 

6. Medium to high strength 287 

b. Dense-burning between cones 10 and 15 296 

7. Mainly medium to high strength 296 

c. Dense-burning between cones 5 and 10 302 

8. Medium to high strength 302 

B. Non-refractory clays 311 

a. Open-burning 311 

9. Medium to high strength 311 

10. Low strength 314 

b. Dense-burning 316 

11. Low strength 316 

ITT. Red-burning clays 321 

A. Open-burning 321 

12. Medium to high strength 321 

13. Low strength 328 

B. Dense-burning 334 

a. With long vitrification range 334 

14. Mainly medium to high strength 334 



CONTENTS 7 

I'age 

b. With short vitrification range :. 338 

ir>. M.dium to high strength 338 

IV. Clays liiirning dirty white, cream white or yellowish white 348 

17. Cenorally contain calcium or magnesium carbonate 348 

Chemical analyses 353 

Index of clay sample numbers 357 

Index of clay samples, by counties 358 

General index - 362 



LIST OF TABLES. 



No. Title rage 

1. Check list of ceramic plants In California 22- 25 

— 2. Brick and hollow tile production for llt26, l)y counties 32 

.'). Common brick production (jf California, l).v years 33 

4. Production of pottery clay in California in 1926 33 

5. Pottery clay production of California, l>y years 34 

6. Value of pottery clay products made in California during l!t2i) 34 

7. California and total United States production of ceramic products from 1896 

to 192C 36 

8. Description of core drill samples from lone district 52 

!t. End points of Orton pyrometric cones m Centigrade and Fahrenheit degrees. 244 

10. Visual correlation of certain Ridgway colors with Munsell colors 251 

11. Key to classification of clay samples tested 258 

12. Drying data, clays of classes 1 and 2 267 

13. Firing data, clays of classes 1 and 2 268 

14. Drying data, clays of classes 3 and 4 274 

15. Firing data, clays of classes 3 and 4 275 

Hi. Drying data, clays of class 5 283 

17. Firing data, clays of class 5 284 

18. Drying data, clays of class 6 293 

19. Firing data, clays of class 6 294 

20. Drying data, clays of classes 7 and 8 306 

21. Firing data, clays of classes 7 and 8 307 

22. Drving data, clays of classes 9, 10 and 11 317 

23. Firing data, clays of clas.ses 9, 10 and 11 318 

24. Drying data, clays of clas.ses 12 and 13 ^''Q 

25. Firing data, clays of classes 12 and 13 33i 

26. Drying data, clays of classes 14 and 15 : 344 

27. Firing data, clays of classes 14 and 15 345 

28. Drying data, clays of cla.ss 17 350 

29. Firing data, clays of class 17 351 

30. Chemical analyses of clays from sampled deposits 354-355 

31. Chemical analyses of miscellaneous California clays, not sampled 356 



LIST OF PLATES. 



No. Title Page 

I. Map showing locations of high-grade clay deposits in California IS 

II. Common brick and cement statistics of California 33 

TIT. Annual value of clay jiroducts in California and in the United States 37 

IV. Map of Tesla district, Alameda County 43 

V. Ceologic section through main Tesla shaft 44 

VI. Property map of If)ne district, Amador County 50 

VIT. Sketch mai) of Clark and Marsh kaolin mine near Calistoga 134 

VIII. (ieneral arrangement of (piarry and plant of the Clay Corporation of Cali- 
fornia, Lincoln, Placer County 148 

IX. Vertical section of clay beds on Clay Corporation of California's jiroperty, 

near Lincoln 149 

X. Property map of Alberhill-Corona district. Riverside County 162 

XT. Diagrammatic section of strata at Alberhill 163 

XII. Handling and storage of clay by the "glory-hole" method 168 



LIST OF PHOTOS. 



No. Title Page 

1. Russ Building, San Francisco Frontispiece 

2. Ryan Ranch clay deposit 46 

3. Filter-press room, Westinghouse Electric and Manufacturing Company 47 

4. Hot-pressing room, Westinghouse Electric and Manufacturing Company 48 



b CONTENTS 

Page 

5. Gage clay pit 53 

6. Jones Butte Mine 54 

7. Barber or Shepard pit 55 

8. Sand Pit subleased by the lone Fire Brick Company 55 

9. Yaru clay pit 56 

10-A. Fancher clay pit 59 

10-B. Brick machinery in plant of lone Fire Brick Company 60 

10-C. Sand pit of the lone Fire Brick Company 62 

11. Valley Springs clay pit 69 

12. California Art Tile Company's ijlant 72 

13. Richmond Pressed Brick Company's plant 75 

14. Plant of Thompson Brick Company 82 

15. Vitrefrax cvanite deposit 86 

16. Malibu Pottery 106 

17. Drying floor, Los Nietos plant of Pacific Clay Products Company 108 

18. Airplane view, Lincoln Heights plant, Pacific Clay Products Comjjany 110 

19. Airplane view, Los Nietos plant, Pacific Clay Products Company 112 

20. Clay bins and unloading crane, Lincoln Heights plant. Pacific Clay Products 

Company, Los Angeles 113 

21. Pug-mill, auger machine and cutter, Lincoln Heights plant. Pacific Clay 

Products Company, Los Angeles 114 

22. Dry pans and twin wet pans, Los Nietos plant, Pacific Clay Products Com- 

pany, Los Angeles County 115 

23. Sewer-pipe press, Los Nietos plant. Pacific Clay Products Company 116 

24. Interior view of plant, Vitrefrax Company, Los Angeles ^ opp. 122 

25. California MuUite brick being fired in tunnel kiln at cone 28, Vitre'rax Com- 

pany, Los Angeles 122 

26. Clay and shale deposit of McNear Brick Company, showing loading hopp r, 

Marin County 125 

27. Clark and Marsh Kaolin Mine 133 

28. Flint fireclay at portal of tunnel. Goat Ranch, Gladding, McBean and Com- 

pany, Orange County 142 

29. M M 2 pit. Goat Ranch, Gladding, McBean and Company, Orange County 143 

30. Plant of La Bolsa Tile Company, Weibling, Orange County 143 

31. Vitrefrax Company, entrance to upper chamber workings, O'Neill Ranch clay 

deposit. Orange County 145 

32. End-cut during preparation of pit of Clay Corporation of California, Lincoln, 

Placer County 150 

33. Clay pit of Gladding, McBean and Company at Lincoln, Placer County 152 

34. Airplane view of Gladding, McBean and Company plant at Lincoln 154 

35. General view of pit and plant, Lincoln Clay Products Company 156 

36 "Eastern end of pit, Lincoln Cay Products Cnmiiany ■> '"' 

?'«.' Western end of pit, Lincoln Clay Products Company 157 

3'S. Valley View Mine, i>ortal of lower tunnel 160 

39. Valley View Mine, upper workings 160 

40. Southwest wall of main pit, Alberhill Coal and Clay Comn-'ny 164 

41. Alberhill Coal and Clay Company, cut connecting main and west pits 165 

42. Alberhill Coal and Clay Company, one of the loading trestles 165 

43. Lower portion of west pit. Alberhill Coal and Clr>v Company 166 

44. Alberhill Coal and Clay Company, exposure of lignite coal 167 

45. Emsco Clay Company, Harrington pit 170 

46. Loading chute, Emsco Clay Company 172 

47. Gladding, McBean and Company. Alberhill. main tunnel pit 174 

48. General view of Alberhill plant. Los Angeles Brick Company opp. 176 

49. Los Angeles Brick Company, Alberhill plant, during construction 177 

50. Los Angeles Brick Company, Alberhill ])lant, timnel driers, during construc- 

tion 177 

51. Los Angeles Brick Company, Alberhill plant, showing drier cars and brick 

represses 17S 

52. East pit, Los Angeles Brick Company, Alberhill 179 

53. Douglas pit. Pacific Clay Products Comi)any at All>erhill 180 

.')4. Cannon and Company's plant, Ben Ali 184 

55. Electric shovel in preliminary cut, Natoma Cay Company 187 

56. Panama Pottery Comiiany's plant, near Sacramento 187 

57. Fancy garden pottery, manufactured by Panama Pottery Company 188 

58. H. F. Coors Kaolin Deposit. Hart. San Bt^rnardino County 194 

59. Pacific Kaolin Mine, Standard Sanitary Company, upper workings 196 

60. Pacific Kaolin Mine, Standard Sanitary Comnanv. lower tnnn-'l leve' 197 

61. "Bear Cat" shovel at Kelly No. 1 mine. Pacific Clay Products Company, 

Farr siding, San Diego County 204 

62. Wiro Mine, fireclay denosit east of Cardiff, San Diego County 205 

63. Plant of the Stockton Fire Brick Company. Stockton 210 

64. Clay bins and dry pans in plant of Stockton Fire Brick Company 211 

65. Plant of San T^uis Brick Works San Tjuis Obisno 214 

66. M'eiss clay deposit, near Glen Ellen. Sonoma County 228 

67. Assay laboratory, Stanford University 242 

68. Fisk pre-mi.x gas-fired laboratorv kiln, in ceramic laboratory, Stanford Uni- 

versity 243 

69. Wilson oxy-acetylene cone fusion furnace in ceramic laborator.v, Stanford 

University 247 

70. Cabinet of fired test pieces, ceramic lalioratory, Stanford University opp. 257 



LETTER OF TRANSMITTAL. 



To His Excellencij, Hon. C. C. Young, 
Governar of the State of Calif onvia. 

Sir: I have the honor to herewith transmit bulletin No. 99 of the 
State Division of Mines and Mining on the Clay Resources of 
California. 

This work deals in detail with one of California's nonmetallic mineral 
ijidustries which is annually growinp' in importance and value. Ceramic 
plants are being established in increasing numbers, existing plants are 
lieing enlarged, and a wide variety of products is being put on the 
market. Our natural deposits of clays in this state form the basis upon 
which these industries are founded. 

This bulletin is the result of over two years' field and laboratory 
investigations conducted by Mr. W. F. Dietrich, associate professor of 
mining engineering at Stanford University; the work being handled 
on a cooperative basis between the University and this Division. 
Acknowledgement is here maile of the courtesy aud cooperatiou of Mr. 
Theodore J. Hoover, Dean of the School of Engineering of Stanford 
University. 

Respect fully submitted. 

Lloyd L. Root, 

State iMineralogist. 



CHAPTKK I. 

IXTRODUCTIOX. 

The scope of this rei)()rt is confined to a study of the raw materials 
and manufacturinji' practice of tiiat part of the ceramic industry of 
California wliich involves the manufacture of products which "are 
molded in the aqueous plastic condition and which derive their strength 
from the iiartial fusion (vitrification) of silicates at hig'h temjiera- 
tures. "^ This restriction excludes ylass, enameled metals, cements, limes, 
l)lasters, and most abrasives, whicli in modei'n parlance are broadly 
considered to belong to tlie field of ceramics. 

The report inchules a brief technical description of most of the clay- 
working plants and known clay deposits in California, together with the 
results of laboratory tests of the important clays of the state.. The 
l)rincipal emphasis is upon the economic and technologic phases of the 
clay-working industry of California, rather tlian ui)on its geologic 
aspects. 

The field work was done in the summers of 1925 and 1926, and the 
total time in the field was five months. In a state luiving 155,652 
s([uai-c miles of land area, it was obviously impossible in the period of 
tile field examination to make detailed investigations of all known clay 
deposits, or to search for new^ deposits not already known to the ceramic 
industry, the Mining Bureau, or to local inhabitants in the possible clay 
areas. Hence the principal value of this report lies in the fact that it 
is a record of progress of the clay industry and presents for the first 
time standard test data on the known clays as a basis of comparison for 
new clays that may be discovered in the future. The uses of many of 
the clays that were tested are very well known from i^lant experience, 
so that it should not be difficult for the intelligent plant operator to 
correlate the test data with the results of commercial practice, not only 
for the clays now in use in his i)lant, but for other clays that have been 
tested. 

The search for high-grade clays on the Pacifie coast has received new 
impetus in recent years on account of the phenomenal increase in 
])opulation in the region and the consequent increased demand for 
structural and decorative clay products. There seems little doubt that 
this is but the beginning of one of the greatest ])eriods of exjiansion 
that the world has ever seen. If this vie-\v of the future is correct, 
California is destined to become one of the great ceramic centers of 
the United States. That new clay deposits will be discovered is almost 
a foregone conclusion. Thus far, only the obvious deposits have been 
found, and only those that can be cheaply mined, and that can be used 
without beneficiation, have been exploited. The geologic column of 
California is practically complete, and there remain many thousands of 
square miles of land that have never been tlioroughly ])rospected for 
clays. Prospectors and local residents away from existing clay pro- 
ducing regions are on the whole unfamiliar with the nature of clays, 
but it is certain that their knowledge Avill improve by contact with 
trained men who are on the lookout for new discoveries. It is true that 
the abundance of cheaply recoverable terra cotta and fire clays has 

1 Wil.son, Hewitt, Ceramics, p. 2, McGraw-Hill Book Co., 1927. 



12 DIVISION OF MINES AND MINING 

heretofore hindered the development of iieAV resources, but with the 
rapid acquisition of the best of these deposits by single manufacturing 
interests, and Avitli the increasing demand for new types of clays, either 
to displace those varieties now being imported from outside of the state, 
or to make improved products, the incentive to clay prospecting will 
be entirely adequate. 



METHODS OF INVESTIGATION. 

The field work on the clay depositvS consisted of a visit to each prop- 
erty to obtain clay samples and to prepare a description of the develop- 
ment and mining operations, tlie thickness of the clay and overburden 
and other features of i^ossible interest. ]Most of the samples were taken 
from exposed surfaces, and due precautions were taken to secure sam- 
ples that were representative of the workable beds of clay. In a few 
places, samples were taken from bins or storage piles, if these seemed 
more suitable for securing representative samples than the clay banks. 
In some instances, samples were submitted by the clay producers them- 
selves as being representative of their deposits. A number of core 
drill samples were obtained from the lone district, through the courtesy 
of S. E. Kieffer. 

The plant descriptions were nearly all prepared by the author after 
an inspection of the plant. Many of these descriptions were submitted 
to the plant executive for approval before publication. A few descrip- 
tions were prepared by members of the organization concerned. 

Descriptions of a number of plants that were started subsequent to 
the field investigation or that were overlooked by the author, Avere pre- 
pared by ^Messrs. Laizure, Logan, or Tucker, district engineers, Division 
of ]Mines and ^Mining. 

The test Avork Avas done in the ceramic laboratory of the Department 
of ^Mining and ^Metallurgy at Stanford University by methods described 
in Chapter IV. 

PREVIOUS WORK. 

The clays and clay industries of California AA-ere described in two 
earlier reports^ of this Bureau. These reports include descriptions of 
knoAvn deposits and of the operating plants, but contain very fcAV data 
on the ceramic properties of the clays. 

Most of the county reports of the Bureau contain descriptions of clay 
deposits and clay-Avorking plants that Avere prepared by members of 
tlie State Mineralogist's staff. In a number of cases these descriptions 
are sufficiently up to date to permit their use in the present report, 
and are reprinted here for the sake of completeness and continuity, as 
the county reports are scattered through a number of volumes of the 
State Mineralogist's reports. 

An important article- on the Alberhill clays by the late J. H. Hill, 
then president of the Alberhill Coal and Clay Company, Avas pub- 
lished bA' tlu' Bui'eau in 192:^. 



' Stiiutural ami Industrial Materials of California: Cal. State Min. Bur., Bulletin 
3S, part 111, pp. i;tu-25y, 190G. 

The Clav Industry in California: Cal." State Min. Bur., Prel. Report No. (, 102 
pages, ly20. 

= Hill, J. H., Clav deposits of the Alberhill Coal and Clay Company: State Miner- 
alogist's Report XiX, pp. 185-210, 1923. 



CLAY RESOURCES AND CERAMIC INDUSTRY 13 

The foraiuif |)r()i)oitios mid cliemieal analyses of certain clays from 
tlie Alberliill district liave bi-en jjfiviMi by I>nrclifi('l.' 

Tlio clay iiiininir and jjropai'atioii plant of tlic Clay Corporation of 
California, at Lincoln, has been described by C. N. Schuette.- 

AU of the foregoing references were freely used in the preparation 
of this bulletin, even at the cost of repetition, as it was desired to bring 
together in one vohnne all of the avaihd)lc infoi'iiiation on the ('la\' 
resources of the state. 

ACKNOWLEDGMENTS. 

In a work of this nature it is impossible to give individual acknowl- 
edgment to all those who contributed to it. The writer wishes to 
express his apjn-eciation of the courtesies that were extended to him by 
many i)crsons connected with the ceramic industry of California. 
Their cooperation in making this bulletin possible is especially note- 
worthy in view of the fact that, on the whole, the ceramic industry 
today remains as one of the few mineral industries that extensively uses 
secret processes and secret formulae. 

Prof. He\\'itt Wilson of the University of Washington rendered 
invaluable assistance in outlining the methods of clay testing aiul in 
making many valuable suggestions and criticisms. 

Mr. John T. Roberts, president of the Stockton Fire Brick Company, 
generously contributed equipment and refractories to the ceramic 
laboratory in which the test work was done, and was ever ready to give 
valuable advice and infoi-mation during the progress of the work. 

^Ir. L. M. Richard, consvilting economic geologist for Gladding, 
McBean and Company, was especially heli)ful in the field in the 
Alberhill-Corona district, and contributed many ideas concerning the 
organization of the report. 

Several graduate students in metallurgy or ceramics at Stanford 
University contributed to various phases of the investigation, especially 
in the laboratory. Among these should be mentioned V. J. ^linner, 
C. W. Brigg.s, H. J. 'Carroll, D. R. Irving and R. E. Paine. 

Acknowledgment is also due to Messrs. Walter W. Bradley, W. Bur- 
ling Tucker and C. A. Logan of the Division of ]\Iines and Mining for 
assistance in compiling data, and for many helpful suggestions regard- 
ing the conduct of the work. In addition, Messrs. Tucker, Logan, and 
C. ]\IcK. Laizure supplied a number of descriptions of deposits or plants 
not visited by the author, acknowledgments of which are made in the 
text. 

GENERAL REFERENCES. 

Little space has been devoted in this report to the origin of clay, its 
chemical and physical properties, or to clay-working processes in gen- 
eral. Such information has usually been included in clay reports from 
other states, but there seems little justification for its inclusion here, 
in view of the fact that there are now a number of excellent texts for 
those who desire such information. A few of the more important 
works are listed below : 



• Burchfiel, B. M.. Refractory clavs of the Alberhill, California, deposits: Jour. 

Amer. Cer. Soc, Vol. 6. pp. 1167-1175, 1923. 

= Schuette, C. N., Engineering principles applied to the exploitation of a clay 

deposit: Eng. & Min. Jour.-Press, Vol. 121, p. 964, June 12, 1926. 



14 DIVISION OP MINES AND MINING 

Wilson, Hewitt, "Ceramics." McGraw-Hill Book Co., New York, 
1927. An excellent text on clay technology, coA^ering the chemical and 
physical properties of clays. Not suitable for readers who have no 
knowledge of chemistry or physics. 

Andrews, A. I., "Ceramic Tests and Calculations." John Wiley 
and Sons, 1928. An elementary text on the methods of clay testing, 
and on the calculations relative to glazes, bodies, enamels and glasses. 

xSearle, A. B., "The Chemistry and Physics of Clays and Other 
Ceramic Materials." Ernest Benn, Ltd., London, 1924. A valuable 
reference work of scientific conceptions and data on clays. Particularly 
useful to research workers. 

Ries, Ileinrich. "Clays, Their Occurrence, Properties and Uses," 3d 
Edition. John Wiley and Sons, 1927. The standard work on the 
geology and origin of clays, with sufficient information on properties 
and uses to serve as an elementary text. Perhaps the best general 
work for tlie layman. 

"Clay Products Cyclopedia and Equipment Catalog." Issued annu- 
ally by Industrial Publications, Inc., Chicago, Illinois. A useful 
reference, of particular value as a dictionary of ceramic nomenclature 
and for the descriptions and illustrations of ceramic equipment. 



to 



CLAY KESOUUeES AXD fEKA.M U' IXDUSTUV 15 



Chapter IT. 
SUMMARY OF THE CERAMIC INDUSTRY OF CALIFORNIA. 

INTRODUCTION. 

For the benefit of those who may be unianiiliar witli ehiy-working 
processes, a brief summary of clay technology is given. 

Definiticyn of clay: "Clays are the weathered products of tiic silicate 
rocks, containing sufficient hydi-ous silicate of alumina in the softened 
condition to ])roduce a ])]astic or semiplastic nuiss when tempered Avith 
water. "^ Clays may be classified into many types. In this report a 
classification is used that is based upon physical properties and uses. 
The details of this classification are given in Chapter IV. 

Definitions of a few of the more general terms used in clay momencla- 
ture are given below :- 

Kaolin is amorphous hydrated aluminum silicate, corresponding to 
the formula of Al20..5.2Si6^.2HoO and is the most important constituent 
of china clay. The term is \ndely used in commercial practice to 
include china clay and rock higli in china clay. 

China clay is the commercial variety of kaolin. It may occur 
naturally in deposits of sufficient purity, but is more often prepared by 
the purification of natural deposits. It burns white, and has high 
refractoriness, but the plasticity is generally poor. 

Ball clays are white or light-cream-burning clays of high plasticity 
and bonding power that vitrify to dense impervious bodies at compara- 
tively low temperatures. 

Fireclays are those clays that withstand high temperatures, par- 
ticularly those that do not fuse at temperatures below 1605° C. 
(2921° F., cone 27). They are used in the manufacture of fire brick 
or other refractories and are often used for architectural terra cotta, 
wall tile, etc. 

Face brick clays maj- be divided into one of three groups. (1) 
Red-burning clay; (2) white-burning clay; (3) buff -burning clay. 
The color, ])lasticity, shrinkage, and vitrification must fall within cer- 
tain general limits, dependent upon the type of brick to be manufac- 
tured. 

Common brick clays vary widely in their composition and proji- 
erties. TJiey are usually high in fiuxes and in most cases are I'ed-burn- 
ing. They should mold easily and develop hardness and strength at as 
low a firing temperature as possible without seriously warping or 
cracking. 

Slip clays are fine grained, and contain a high proportion of fluxes. 
They should melt at a low temperature (preferablj^ below 1200° C, 
cone 5) to a greenish or brown glass to form a natural glaze. 

CJaij preparation: With the exception of some of the lieavj^ struc- 
tural products, it is seldom possible to find a single raw material that 

• Wilson. Hewitt, Ceramics. ]). 7. 

= See Wilson, op. cit.. pp. 28-39, and Clay Products Cyclopedia, 1926, pp. 94-96, for 
further details. " ' 



16 DIVISION OF MINES AND MINING 

possesses the desired plastic, tli yi(i<i' and lirin<>' cliaractcri.stics tor mak- 
ing a given ceramic product. It is usually necessary, therefore, to 
blend several clays and nonplastics in order to control the properties 
of the finished ])roduct. For example, clays having different per- 
centages of iron may be blended to secure the desired color ; highly 
]dastic clays may be blended with those having poor plasticity in order 
to control shrinkage and porosity ; feldspar may be added as a flux to 
lower the temperature of vitrification; crushed qiuirtz or crushed cal- 
cined clay may be used as a "grog" to produce a skeleton structure 
that is bonded by the clay, giving greater strength and less tendency 
to warp than if clay alone were used. 

After deciding upon the proportions of the various raw materials, 
some of them are ground separately and others are ground after mixing, 
either by dry or wet methods. Ball mills and grinding pans are the 
principal types of machinery used for fine grinding. At some point 
in the process, all the materials are mixed together, the proper amount 
of water is added, and the mass is subjected to a thorough mixing, with 
or without additional grinding. For the manufacture of many types 
of ware, the plastic mass is allowed to age in humidified rooms or under 
wet sacking for a period of 24 hours to one month, in order to secure 
uniform distribution of the water and to develop maximum plasticity. 

Manufacturing processes: After the clay is properly prepared, the 
three essential steps in the manufacture of a ceramic product of the 
type under consideration are shaping, drying and firing. A fourth 
l)rocess that is applied to certain types of ware is glazing. 

Shaping": The shaping of clay wares may be done while the clay is 
in one of the four different degrees of plasticity: (1) Drj^ pressing of 
pulverized mixtures to which has been added just enough water to bind 
the mass together when subjected to pressure in hydraulic, cam. or 
screw presses. This process is principally used for shaping floor and 
wall tile, especially the hard vitrified tile used in bath-room floors, and 
to some extent it is used in common brick and face brick manufacture. 
(2) Stiflf-mud shaping, in which si\fBcient water is added to tlie clay to 
permit the mass to floAv through a die without rupture. A column of 
clay is pushed through a hollow die by a plunger or screw or the clay 
may be jiressed into a steel mold by a plunger. This is the usual 
process for making common brick, face brick, fire brick, and roofing 
tile, and is the only method in use for shaping hollow tile, sewer pipe, 
drain tile, and electrical conduit. (3) Soft-mud shaping, in which 
almost enough water is added to cause stickiness. This consistency is 
used for the hand pressing of terra cotta and tile in plaster molds, for 
the shaping of pottery and stoneware on pottery wheels or in molds, 
for the hand molding of roofing tile over paper covered wooden molds, 
or for the hand or mechanical pressing of common brick or face brick. 
(4) Casting, in which the finely-ground mixture is suspended in water 
so that the resultant "slip" may be poured into plaster molds. The 
plaster absorbs water from the slip, gradually precipitating the solids 
asainst the inner walls of the mold. When the Avails are thick enough, 
the surplus slip is poured from the mold, the object is left in the mold 
until stiff enough to stand its own weight, then the mold is stripped 
off and the shape allowed to dry. Casting is the cheapest method of 



(LAV KES0UKCE8 AND C'EKA.MU INDL'STKV 17 

producing pottery on a large scale, and is the principal method in use 
for shaping sanitary porcelain. 

Drying: The drying of clay wares may be done under sheds in 
the open, in specially heated rooms, or in specially designed humidity 
dryers in which the three factors of time, temperature and humidity are 
under close control. The type of drying will depend upon the charac- 
teristics of the clay used and u])on the sliape and size of tlie ware to be 
dried. As clay shrinks dvirinu drying, it is important that the drying 
be controlled in such a way as to avoid undue strains which might 
cause cracks in the dried ware, or lines of weakness which would i-esult 
in cracks during the subsequent firing operation. 

Firing: The i)roper firing of ceramic ware is perhaps the most 
important part of the process, and many tyi)es of kilns are available 
for the purpose. The essential conditions to be met by a ceramic kiln 
are control of the time-temperature cj^cle and unifoi-mity of heat dis- 
tribution. In some cases, kiln gases can not be allowed to come in 
contact with the ware, so that mufiie kilns are necessary, or else the ware 
is enclosed in fireclay receptacles known as "saggers." Most kilns 
now in use are of the periodic type, but there is a growing tendency to 
use continuous kilns in which the ware is set on trucks which move 
through a tunnel that is fired near its mid-point. Firing temperatures 
range from 895° C. (1643° P.) for soft-burned common brick to 
1350° C. (2462° F.) for hard porcelain and fire brick. A few special 
products are fired as high as 1640° C. (2984° F.).^ 

Glazing: Glazing may be done by dipping, spraying, or painting a 
water suspension of the glaze ingredients on the ware either before 
firing, or after a preliminary (biscuit) firing. In some cases where 
complicated polychrome decorations are used, several firings are 
necessary before the piece is finished. Salt glazing is another method, 
wherein common salt is vaporized in the kiln during firing, the 
sodium of the salt reacting with the clay body to form a fusible com- 
pound. 

CLAY DEPOSITS OF CALIFORNIA. 

hi practically all of the low altitude areas of California there is an 
abundance of common clay and shale suitable for the manufacture of 
common brick and hollow building tile. By reason of the low unit 
value of these ])roduets, the raw material must be chea]")ly mined, and 
will not stand transportation charges from points very distant from 
the brick yards, which are situated near the centers of consumption. 
In the San eloaquin and Sacramento valleys, it has been difficult to 
find good bodies of clay with sufficient plasticity for the manufacture 
of the best quality of building brick, and some of the plants in this 
area have been forced to ship plastic clay from dift'erent points to 
mix with the local materials. In the San Francisco Bay district and 
in Los Angeles County, the two important centers of consumption, 
there are ample common clay resources. The same is true of the 
smaller valleys in the Coast Range and in the foothills of the Sierra 
Nevada. 

In the mountainous portions of the state, in the desert regions, and 
in the volcanic area of the northeastern counties, it is difficult to find 



1 Pyrometric cones are extensively used in the ceramic industry as temperature 
indicators. See table No. 9 in Chapter IV. 
2 — 54979 



18 DIVISION OF MINES AND MINING 

suitable coinniou brick clays, but as these areas will probably never be 
thickly populated, such brick as are needed can be shipped in from 
more distant points. 

Tlie demand for paving brick lias never been great enough to k'ad 
to an intensive search for red-burning shales of the type used elsewhere 
in the United States for paving brick manufacture. A few such shales 
are known, and one or two deposits are being worked, but, for the most 
part, the demand for paving brick, sewer pipe, conduit pipe, and other 
red-burned vitrified products has been met by a blending of various 
clays, with or without grog. Three deposits are of special interest in 
this connection: the Natoma da}' (see samples No. 210 and 212), 
which consists of fine gold-dredge tailings deposited in settling basins ; 
the Goat Ranch shale (see sample No. 282), an Upper Cretaceous shale 
in Santa Ana Canyon; and the Santa ]\Iargarita shale (see samples 
No. 216 and 217), from an undeveloped deposit along the Southern 
Pacific Railroad near Santa IMargarita. 

The general distribution of the high-grade clays of California is 
shoAvn on Plate I. 

The high-grade clays of the state are found mainly in deposits of 
Eocene age, although there is one important area of Pleistocene clay, 
and the importance of certain beds in the Upper Chico (Cretaceous) is 
just receiving recognition. Approximately 90 i)er cent of the high- 
grade clays of the state are now being mined from one of three areas: 
the Alberhill-Corona district in Riverside County ; the lone district in 
Amador County ; and the Lincoln district in Placer County. The age 
of the clays in all three districts is Eocene, and the dei>osits were 
formed by sedimentation in inland seas, with or Avithout subsecpient 
alteration. 

The Alberhill-Corona clays occur in an area in the Temescal Valle}' 
some twelve miles long and two miles wide. In many places the clay 
beds are three to four hundred feet thick. The clays were laid down in 
Eocene time in an arm of the sea. The region is characterized by a 
discontinuity of structure that arose from folding, faulting, and erosion 
subsequent to clay deposition, and by extreme local variations in the 
individual clay beds caused by variations in the conditions of sedi- 
mentation. A wide variety of red, pink, and buff-burning i)lastic clays 
and a good range of plastic and semi-plastic fireclays are produced in 
the district. The colored clays are used for face brick, roofiug tile and 
red earthenware, and as an ingredient of sewer pipe, electrical conduit 
and other mixes. The buff-burning clays, generally refractory, are 
used for architectural terra cotta, stoneware, decorative tile, pottery, 
etc. The refractory clays are used for fire brick and other refractory 
shapes. A few selected varieties are sufficiently free from coloring 
compounds to ])ermit their restricted use in white-burned products. 
The typical clays are chai-acterized by excellent plasticity, low or 
medium dry strength, low or medium drying and firing slirinkage, and 
open fired texture. A few varieties are found that possess high dry 
strength and high shrinkage, and that vitrify completely within com- 
mercial firing ranges, but these are the exception rather than the rule. 
The proportion of sand in the clays varies widely from almost pure 
sand to pure clay, resulting in a wide range of commercial varieties. 

The lone clays and sands occur in a belt about twelve miles long and 
one-half to one mile wide. The total thickness of clay is not knoA\Ti, 



PLATE I 



SISKIYOU 
^^ 



■^-:-TC:.T 

I M D 8 C I 



■CALIFORNIA STATE MINING BUREAU- 
Llovd L. Root 

iTATE MINERALOGIST 

OUTLINE MAP 

• Of 



CAUIORNIA 



SCAIX 



alturas 



izi 



' ) i'l 

A...S. \ -"•■•-'' SHASTA, 

. « 'iRINI-n' L A S 5 E M 




^■■■| 



T E H A M A(^ PLUMAS I 

< ,.., ^ ^^ . 

-eLEHN/BUJlE^.^S, ERRA 
1 -..?-s-,„„>„ .- >"->.l_| 



[MiKDOCINO .! Z"^"-ij°'°""-' I 




SHOWING 
LOCATIONS OF HIGH-GRADE 

CLAY DEPOSITS 

FROM WHICH SAMPLES WERE TAKEN. 

JANUARY. 1928. 

ACCOMPANYING BULLETIN No. 99. 



SAN FRANCISCO^ V'O.'rTB • ^■^' '^ '"" N \ 

5kHT» C«Ui y' -J /. »A «*r(^ / ^ IMD(Pft»01HC[ X 

^ J e^, 5»N ^»,.,..o_r- -■ 1 N Y 0\ <5 

C"""'^ \aCNlTO • * '< p«.«... N, 

UnteSCV^--^ ,„. ... /•"•?"(' •t U L A R E \ ^ 

\ ^^:^ _ '^z , "--\ 

f , o, K 'E P N I • >. 

/ ° "=." I S A N . B E R N A R D 1 N 
< ; . _l "-."i •'-"" .,.„„ 

_ \S»HTA BARBARA , \ ! 

^ J I \ I 

^ ^..ui.o.o VENTURA* -.,_ 

^^VtnTUWA ^ 5»NBEIINAR0lt1O .. " 

<^ V. l05«~6tUS ® ^- 

■='<^^;>' \ * _ /' ' 

^ CX. »^V "'45*^'" R 1 ^ > " ^ 

'*' 5.rA. •"« ^f •nil.. 

\ *... ^.-^^ • '^^ PERIAL 
\«SAN DI EGO . 



MEXICO 




"*"' 



54979 — facing pasre 18 



CLAY RESOURf'ES AXD fERA:Mrr INDUSTRY 19 

but in a nuinber of places a tliiekness of over 100 feet lias been demon- 
strated. The beds are more continuous, and have less local variations 
in the character of the material, tlum is the case at Alberhill. The 
area is important for its liiyh-yrade (iiechiy and tire-saiui. Some plastic 
pink- and buft'-burnin<>: clays are also produced for use in terra cotta, 
stoneware and pottery manufacture. The fireclays are the most 
refractory that have thus far been found in the state, but are charac- 
terized by low dry strengtii and high firing shrinkage, with a strong 
tendency to crack when fired. The fire-sands are composed of quartz- 
mica saiul with from 10 to 25 ])er cent of clay, and are im])ortant as a 
nonplastic ingredient of fire brick mixtures, to diminish the shrinkage 
and the tendency to crack. Future develoi)ments in tliis area are 
expected to greatl.y extend the known dimensions of the clay beds, and 
to disclose other varieties of clay not now accessible. 

The Lincoln clays lie in an isolated remnant of the lone formation 
(Eocene), protected by a lava capping. The beds underlie a low hill 
adjoining the toAvn of Lincoln. The claj^ is continuous over an area of 
about four square miles, to a depth of ap])roximately 100 feet below 
the lava capping. The Lincoln clay is an excellent butf-burning plastic 
fireclay that is especially valuable in the manufacture of architectural 
terra cotta, faience tile, fire brick, and other products. There are also 
beds of pink-burning clays that are used in seAver pipe, roofing tile and 
face brick mixtures. The Lincoln clays have excellent plasticity, 
medium dr}- and fired strength, a long vitrification range, and, although 
the shrinkage is high, the clay can stand rapid firing without cracking. 

Some other clay producing areas of lesser importance are: (1) The 
Cardiff-Carlsbad area in San Diego County, containing excellent 
fireclays, some of whicli are closely similar to the famous (Iros-Almerode 
fireclays of Germany; (2) The Santa Margarita Rancho deposit, near 
San Juan Capistrano, San Diego County, containing important deposits 
of higldy aluminous fireclay; (8) The Hunter Ranch deposit, near El 
Toro, Orange County, where there is an excellent firecla.y, associated 
with a bed of kaolin and sand from which a high-grade kaolin can be 
recovered; (4) The Goat Rancli deposit, in Santa Ana Canyon, Orange 
County, an TTpper Chico (Cretaceous) deposit of flint fireclay. 

California is especially favored with resources of noni)lastic ceramic 
materials. At Campo, San Diego County, is a large de])osit of excel- 
lent felds]iar. and many other feldspar deposits are known in southern 
California. Silica is available in many forms in California and near 
the border in Nevada. A large deposit of quartzite has been found in 
the desert south of Barstow, from which silica brick is being made. 
Talc, used in some floor-tile bodies, is available from a number of 
sources. The most extensive deposits of andalusite and cyanite in the 
United States occur in California. These minerals are of increasing 
importance in the manufacture of high-grade refractories. 

The most im])ortant ceramic materials that are thus far lacking in 
California are ball and chitia clays equal in purity and iniiformity to 
those from the deposits of England or from the eastern T'^'nited States. 
A clay possessing the projierties of a mixture of the two varieties has 
been found in San Bei-nai-dino County, and a good china clay has been 
found in Nevada, but thus far ])roduction has been small, and most of 
the ball and china clay requirements of the California industry are met 
by importation from the eastern states or from England. One of 



20 DIVIRIOX OF MIXES AND MINING 

the factors that lias liindered the establishment of a local clay Avash- 
ing industry to produce china clay is the low price of Beljiian "lass 
sand at Pacific coast ports, making: it unprofitabh^ to market tlie (piartz 
sand which would be a by-product of kaolin waslnng-. Since the yield 
of kaolin would be but 20 to 30 pec cent from the known deposits in 
California, the importance of a satisfactory market for the sand is 
apparent. 

Wliile a few small deposits of bone clay have been found in southern 
California, highly aluminous clay is relatively scarce, and no commer- 
cial deposits of diaspore, bauxite or gibbsite^ have been discovered in 
California. 

MINING METHODS. 

Most of the clay deposits of California are mined by open pit 
methods, and with the exception of most of the common clay deposits, 
hand methods predominate. Where a production of the order of one 
car (50 tons) per day or more is needed mechanical methods are in 
general use, if topographic features are favorable, and if no hand sort- 
ing of the clay is necessary. 

Drilling and blasting are necessary at many of the deposits. The 
holes are usually drilled with hand augers, and blasted with light 
charges of low-power explosives. As a rule 3 nearly vertical bank is 
carried, and the height of the bank corresponds to the thickness of the 
bed being mined. Stripping of overburden, if any, is carried out in 
advance of mining, on a separate bench. 

The hand methods in use involve pick and shovel loading into auto 
trucks, wagons, mine cars, wheelbarroAvs, or loading chutes, depending 
on local conditions. 

The mechanical methods include horse-drawn scrapers. ]iower-driven 
drag scrapers, and power shovels of various types actuated by gasoline 
or electricity. The scrapers usually load directly into hoppers, from 
Avhich the clay is drawn oif into auto trucks, industrial railway cars, 
or onto belt or bucket conveyors. The shovels load into auto trucks, or 
into industrial or standard railway cars. 

Most of the underground mining is done by the room aiul pillar 
method, from a tunnel entry, with only such auxiliary timber support 
as is necessary to support localized blocks of loose ground. While 
pillars are robbed as much as is practicable, from 20 to 35 i)er cent of 
the clay must be left in the pillars to support the workings. 

Transportation from the pit to the plant or railroad siding is done at 
many properties in the original vehicle in which the clay is loaded. At 
other properties a loading platform or chute is placed as near the pit 
as possible, and the clay is transferred to cars on an industrial railroad 
or into auto trucks. 

Most of the clay mining in the state is done on contract, especially 
at smaller properties. To one familiar Mith metal mining, the methods 
in use at many of the properties seem needlessly crude and wasteful of 
human energy, but the short working season, seldom longer than from 

1 These three minerals are t\'pes of aluminum hydi -)xide. Diaspore contains 12-14 
per cent of water and has a formula approximating to AloO^i.HoO. Bauxite contams 
20-24 per cent of water and corresponds to AI0O3.2H.O. Gibbsite contams 27-3o 
per cent of water and corresponds to AloO.-..3HoO. See Searle "The Chemistry and 
Phvsics of Clavs," p. 3.39. The bauxites are used in the manufacture of metallic 
aluminum, and' are valuable for the manufacture of a .superior type of fire brick 
(diaspore brick) that is more refractory than ordinary fireclay brick. These 
brick are used, among other purposes, for lining the clinkpring zone of cement kilns. 



CLAY RESOURCES AND CERAMIC INDUSTRY 21 

'Siny to October, the eoinparatively small seale of operation, the fluctua- 
tion of demand, the irre«iularity and small size of some of the deposits, 
the necessity of hand sortin.n' in a number of cases, and the fact that 
many of the deposits are mined uiuler a royalty lease, all must be <riven 
due consideration before any valid criticisms can be made. 

Clay minintr costs for oj^en i>it work range from 10^ to 25^' })er ton 
for scraper or shovel loading, to 2()(^ to aO^ ])er ton for hand loading. 
Hand sorting nuiy double the cost of liaiul loading. Transportation to 
the pit mouth, or to a bin within a few hundi'ed yards of the pit, may 
add fi-om o^ to 2o^'- ])er ton. liieidentals may total from 'h- to 25^, 
making the total direct cost vary between the approximate limits of 20^ 
and $1.50 per ton. In addition, many of the properties are several 
miles from a railroad or plant and must stand a transjiortation cost 
that may be in excess of $1 per ton. The longest auto truck haul noted 
was 15 miles, aiul there are a number of deposits where the haul is from 
thi-ee to eight miles from the pit to a railroad or plant. Where a 
royalty is paid, the charge is usually from lO^'- to 25^ per ton. 

rnderground mining- costs are naturally higher than open pit costs, 
but the direct cost of mining and loading, including hand sorting, is 
seldom in excess of .$1 per ton. Haulage and t ranspoi'tation costs must 
be added. 

As an indirect indication of costs, the selling prices of a number of 
clays may be cited : The price of Alberhill clay f.o.b. gondola cars at 
Alberhill ranges from $1 per ton for the cheaper grades that occur in 
large deposits and that are chea))ly mined by mechanical methods, to 
$5.50 per ton for the rarer varieties that are hand sorted and may be 
mined by uiulerground methods. The price of Lincoln clay, mined by 
a ])ower shovel from a large ])it. is nominally $1.75 ]ier ton, f.o.b. 
Liiu;oln. 

CERAMIC PLANTS. 

A check list of tiie clay-working jilants of (•alifornia, with the 
products made in each, is given in Table 1. It will be noted that the 
majority of the plants in the state are in or near the two major centers 
of po])ulation and industry, the Los Angeles area, and the San Fran- 
cisco Bay district. However, common brick and hollow-tile plants are 
well distributed among the lesser centers of population, and there are a 
number of important manufacturers of high-grade ceramic products 
whose ]>lants are at some distance from the larger centers. Some of the 
plants in the latter group have been built adjacent to clay pits in order 
to secure close coordination between the clay quarrying and the manu- 
facturing plant. Since freight rates on finished products are higher 
than on raw materials, it is advantageous to locate the i)lant near the 
geogra])hical center of consumption of finished Avare. 

The check list also reveals the wdde diversity of the California 
industry and sliows that nearly all of the ceramic products now in use 
are manufactured wi one or more California plants. The important 
excei^tions are magnesia brick, chrome brick and chemical porcelain 
and stoneware. Magnesia brick were made for a short time during 
the World War. Avhen foreign supplies were unavailable, and earlier 
attempts were made by various companies, but the business is 
uneconomic under normal conditions. 



22 



DIVISION OF MINES AND MINING 






o 



Cast iron 
enameling. 



Porcel in 

specialties. 



Electrical 
insuhtors- 



Flower pots, 
olla9, etc... 



Stoneware. 



Sanitary ware. 



cc 

O 



< 



u 

3 
Q 
O 

oc 

Q. 



< 



CC 

o 



o 






< 
cc 

UJ 

u 
Ik 
o 

I- 






X 

o 



z 

UJ 






Art or garden 
pottery 



Kitchenware. 



Tableware. 



o 



o 



Special 
refractories - 



Silica brick. 



Fire clay brick... 



Wall and fire 
place tile.. 



Floor and 
terrace tile. 



Flue lining and 
chimney pipe. 



Roofing tile. 



Conduits. 



Terra cotta. 



Hollow block. 



Drain tile. 



Sewer pipe. 



Face brick - 



Paving brick. 



Common brick. 



no 
•r* OS 






C 

I 



o 
cSoo 






c: ci.5 
rt c3 rt o 






C3 ra C3 .^ • 1.-,^ y^^ _^ '-^ 



, dl^ 



o 
O 

go-" 

.S-- 3 CD o 

a; 

3 



o 
bo 






Ci 



pa 






J « 



O 



O 

c«0(aS 

-*- L^ 'C 0.1^ 

.— t- ty- £- -rr 

£ ",= = 5 



,0 

OH 



g o 



E 



a 






5 
s 

o 



o 



CLAY RESOURCES AND CERAMIC INDUSTRY 



23 



X 










X 


X 


X 










X 


X 


K 




X 










X 




X 


X 










X 


X X 










X 




X 




X 








X X 


M 


X X 










XX X XX 


X 


XX X 










XX XX 


XXX 


X X 












X 


X 










X X 


X 


X XX 




X 








X 


X 






X 








X 


X X 




X 










X 












X 


X 












X 


X XX 






X 


X 


X X 


X XX 


XX X 


XX X X X X X X 


X 



o 



n 



o 

C 



s 



o 
O 



^ o 
SO 

§^ 
CO >> 

25 

X O 






o 

:o 

;:=o 

a 3 





, , ', 6 






6 ; dO 






O 'O m 






o d QJ « 


u 




so— = 


■« 


c 


H>>^-g 





d^^ 



c 2 S 2 rs 

0:^-5 2^ 

'^ £ 5 a = 
cj *- 'tZ "tir 'c 

C C3 1; o cj 

S£ £ G S 






O 

^ c d 9 









l-iixioc 



SS ^_, ^'^ X"^ -y. ;-n . ^ u *^ 



^^£■5 









5oo 

:33a 



•1^ 



o 

"^ ' OS c c 

j^ J ^ 



aj3 



« c =: 
a k fe03 



= ■£:■:=.= Hr« 



•i -r; • >^ '^ 






C'C Cj ^ ^ ?- — 



^ ^ .z: ^ 2 3j 



-. .mm 



:J3 • cs = H-S-i 



'm-^'cCwwSCswccs— u:^-:!^ 



c^m 



j n — (Cm 
: ^ at - 

:m = = 5 









i- ■— 



o 
... - S 



o o »; ca 



odd 
.COO 

jSm^ 

m-a o 



o 



-^, =-n " 



o 






£m; 



^ •- r" -t:; *- <" «^ • 

E £ c 3 .r .2 -"^ - 
K cc H H > >: :S : 



-a _• 
"o 2 



24 



DIVISION OF MIXES AND MINING 



u 

I 
a 

UJ 

oc 

3 
I- 
U 

< 



< 

CO 

f- 
o 

3 
Q 
O 
OC 

o. 






cc 
o 



< 



CO 

I- 



< 
oc 
llJ 
u 

ll. 
o 

H 



o 



X 
u 



CO 

< 



-a 



S 

o 



Cast iron 
enampling. 



Porcelain 
gpcci-iltips^ 



Electrical 
insuhtors. 



Flower pots, 
ollas, etc- 



Stoneware. 



Sanitary ware. 



Art or garden 
pottery 



Kitchcnware. 



Tableware. 



Special 
refractories. 



Silica brick. 



Fire clay brick. 



Wall and fire 
plice tile.- 



Floor and 
terrace tile. 



Flue lining and 
chimney pipe. 



Roofing tile. 



Conduits. 



Terra cotta. 



Hollow block. 



Drain tile- 



Sewer pipe. 



Face brick. 



Paving brick. 



Common brick. 



Q ° 



E 
a 



o 



X X M X X X X 



X XX 



I 



Tj» CO o— o «-H (M -^ 1-1 ,— I -^ ^- — . re tc r- 00 c^ re ro ro -^ ic r>- 1— 
c^ (M ccco -^— Tj"'-j« ic t^r^oooo oeoooooooo OOO'-f- <^^ 



o 



33 

L- 

a 

o 









"S'- !: 






J . ° ?r ^ C '- 



o -^S KC-So c c^=:i iis£^> 



, • t . . o 

>> . . u c 

_; £ " ■ -a g 

S " M t-' '£ § 



dO=8 

■Sh-c: 

— ."x txi:; 
d =o - CC - 



■ h 
;s 

I h. 
. o 

= •2 

■s o = 

3 — -S 



M — *" 






:s s c 



CLAY RESOrUCES AM) ( EKA.MU IXUUSTKY 



ZO 







— 






— 













X 


>: 






X 




M 










X 


V. 


X X 








X 


X X 




















X 


















^ . 












y 




X 


X 






X 




X 


y 




X 







X 


X 










X 








X 




X 


X 


X X 


X 




X 


X X 


X 


X 


X X 


X 


ooooo 


cc 


•o 


oooo 






CI 


■^ ■* 


CC 










— (M C'l CI C*l CI CO 


CO 


cc 


cccc 


cc 


C'llMO 


cs 


(N 


(NC^ 


CI CI CI d CI CI CI 


CJ 


M 


CI CI 


CI 






E 












j 
















































3 








































V 




















3 




c ■ . I 1 I 
















3 


• ' 


■us ; : ; ; 








1 




o 






m b« 


- ■" - o 


(33 




•>> 


1 


c 




X 


:s 


£i5 


c5J-5 'y 
5 >a:":;«8 d ■ 


d 


5| 
.2 S 

-c o 

= 9 


d 


^-j; •" 


,^ 


fe 




£^^-€^a o 


w 


H 


u 




cs 

■r. 


as 




>- = -■- C c t. H 


5 






P3 


5 c c 




^ 


3 s 


^ j ^ ^ 4 — ^' 




n 




sS s 




« 


M zi 


£ i: - = = ==« 


Ci 


e. 


~ o" 




j/ia: v: 


'X. 


■s 


<2 


CU:S;^cg-^M 


o 


vi 


<Sh 


S 


1 












1 


i 






I 






cj 


































"3 


C 


g 




S 

C3 


































ca 


o 


a 




?? 




^ 




^ 




S3 


is 

C3 


t 


3 


_J 


























C 


J3 






















c; 




!/: 




a: 


a: 


-Sl 


OT 




H 


H 


'' 


>■ 



1-s 

■i ^% 
s >;^ 

c = 

O " 



3 

•a 
o 



o 



X 



= ^ 



— jipa S3 

rt t- 3 I-. 

c o^ g 



^ O CJ C 



26 DIVISION OF MINES AND MINING 

MANUFACTURING METHODS IN CALIFORNIA PLANTS. 

Common brick: In California, one common brick plant uses the 
dry-press process, and the other plants are nearly equally divided 
bet-u'een the soft-mnd and the stiff-mud process. Nearly all of the 
plants use drying sheds in tlie oi)en, but some use drying racks in an 
enclosed and heated building, and a few use waste-heat or separately- 
fired tunnel driers. Field kilns are preferred in southern California, 
where there is little rainfall thi-oughout the year, and continuous kilns 
of the Hoffman type are preferred in northern California. Oil is the 
usual fuel for the field kilns, although natural gas is used at some 
plants which are located near the oil fields. At some plants, gas is 
used during the water-smoking period and oil for the balance of the 
firing cycle. The continuous kilns are fired with coal. Firing tempera- 
tures range from cone 08 to cone 1 (950° to 1160° C). 

No mechanical hacking, setting or loading machines are in use in 
California. So far as could be ascertained, none of these devices have 
been given a trial in the state. It would seem that even though such 
machines in their present form may not be entirely satisfactory, the 
hope of saving from 25 to 40 man-shifts per 100,000 brick would be a 
sufficient inducement to encourage the development of automatic brick- 
handling machines, especially in the larger plants. 

Hollow Mock: All hollow block are shaped in auger machines. Some 
of the plants making hollow block are also making common brick and 
both products are subjected to the same drying and firing treatment. 
Waste-heat or separately-fired tunnel driers are in use at a number of 
l^lants. Field kilns are widely used, but several plants use Hoffman 
kilns, one uses a Haigh kiln, and a few use use round do-^-n-draft kilns. 
Firing temperatures are usually between cone 04 and cone 3 (1060° to 
1170° C). 

Face hrick: Most of the face brick of California is shaped by the 
stiff-mud process. Much of it is repressed. The dry-press method is 
used at a few important plants. Drying is usually done in waste-heat 
tunnel driers, and round down-draft kilns are used at all plants for 
firing.^ The firing temperatures usually approximate cone 02 to cone 
5 (1125° to 1205° C). 

Sewer pipe: All sewer pipe is made in presses which are usually 
operated by electric power. Drying is done on drier floors which are 
usually heated by steam or waste heat from the kilns. Round down- 
draft kilns are used for firing and the firing temperatures range from 
cone 02 to cone 5 (1125° to 1205° C). The dry strength of some of 
the sewer pipe mixes in use in California is too low^ to permit setting 
to the full height of the kilns, so that the capacity per kiln is not so 
great as at most of the eastern plants where stronger clays are available. 

Drain file: There is little demand for drain tile in California and 
it is only made in a few plants, where it is sha]ied by auger machines, 
di-ied on heated drying floors and fired in round down-draft kilns. 

Terra cotta: Architectural terra cotta is an important product in 
California. A particularly fine example of its use is shown on the 

1 The wide range of colors demanded by modern architectural design is secured by 
varying the body mixture and by the normal differences of temperature at different 
liarts of tlie kilns. 



CLAY RESOURCES AND CERAMIC INDUSTRY 27 

frontispiece, Plioto No. 1, which is a view of the Kuss Building, in San 
Francisco. The typical body in use in California consists of a siliceous 
plastic fii-eclay mixed with an equal weight of nonplastics, such as quartz 
sand and grog made by regrinding rejected terra cotta from the i)lant. 
This produces a body liaving an absorption of about 15 per cent, when 
fired to cone 4 to 6 (1190° to 1230° C). The mixing, pugging and 
aging of tlie body mix is highly important, and due precautions are 
taken at all ])lants 1o ensure uniformity of the plastic mix that is sent 
to the pressers. All shapes are made by hand pressing in plaster molds. 
After drying to leather liardness, the molds are stri])ped and the ])ieces 
are finished by hand, after which they are dried and s])rayed with 
glaze. A few Carrier humidity driers are used in California in place 
of the usual method of drying on heated floors. In California, the ware 
is fired to cones 4 to 6 (1190° to 1230° C.) in round down-draft kilns. 
A considerable quantity of garden pottery is made in California, 
either as an auxiliary product in the terra cotta plants or in smaller 
plants making a specialty of this class of ware. The body mix and 
manufacturing methods are similar to those used for making terra 
cotta. 

Conduits: Electrical conduits are shaped by auger machines, using a 
mix similar to that used for sewer pipe. ]n California, they are usually 
dried in waste-heat tunnel driers. Round down-draft kilns are used at 
all plants. 

Roofing tile: Roofing tile is popular- in California on account of the 
l)revalence of KSpanish architecture. Hand-made or hand-finished 
machine tile is in considerable demand for the better class of homes, and 
machine-made tile is widely used on homes, apartment houses, hotels, 
schools and even on office and public buildings. Most of the hand-made 
roofing tile plants are small and have little equipment. Drying is done 
under sheds or in a barn, and firing is done in simple rectangular or 
vertical kilns, most of which are up-draft. There are a number of 
large plants making machine-made tile with an auger machine. Many 
of these use waste-heat tunnel driers. Beehive kilns are in general use 
at these plants, but one plant uses a tunnel kiln. Firing temperatures 
approximate cones 06 to 02 (1015° to 1125° C). Several plants pro- 
duce a hand-finished machine tile and finish the upper surface by hand 
before drying is complete. Such tile has nearly the same appearance as 
hand-made tile when laid on the roof, but is considerably cheaper. 
Present-day architectural design calls for a wide range of colors in 
roofing tile, as in face brick. With machine tile, the color range is 
secured by varying the proportions of buff- and ])ink-burning clays that 
are used with the red-burning clay body, and by sorting the diff'erent 
colors produced in different parts of the kiln. In the manufacture of 
hand-made tile, the mix is seldom varied in a given plant, but the color 
variations are obtained by normal variations in firing temi)erature in 
dift'erent i)art,s of the kiln. In fact, the kilns are so small and so simple 
in design that it would not be possible to secure a uniform burn of the 
entire kiln. Individual tile usually show a considerable color differ- 
ence between opposite sides or ends of the tile. This feature, together 
with the irregularity of outline, largely accounts for the artistic value 
of hand-made tile when applied to moderately small roofs. It should 
be noted, however, that hand-made tile can not be relied upon to make 



28 DIVISION OF MINES AND MINING 

a water-proof roof, on account of high porosity and cracks in many of 
the tile. They are often laid over machine tile. 

Fhie lining: ]\Iany of the fire brick and architectural terra cotta 
phmts in California and some of the sewer pipe and roofing tile plants 
make flue lining to supply the trade within their marketing territory. 
A siliceous refractory mix is used, similar to that used in architectural 
terra cotta or in low or mediunl-duty fire brick. Eound shapes are 
made in a sewer pipe press, and square shapes are made in an auger 
machine or by liand pressing. Waste-lieat tunnel driers or hiunidity 
driers are sometimes used, but a connuon method of drying is on floors 
in heated rooms. 

Floor tile: There are a number of important plants in California 
that make vitrified floor tile by the dry-press process. Englisli or 
Florida kaolin and English, Kentucky, or Tennessee ball clay are 
usually used in wliite tile, together witli California or Arizona feldspar 
and California or Nevada silica, although Illinois silica or Belgian sand 
is used at times in place of California silica. Some plants have intro- 
duced California talc into white vitrified tile bodies witli considerable 
success. Colored tile are made bj' substituting colored clays or by 
adding coloring compounds in the proper proportions. Power-driven 
presses are gaining in favor at the larger plants for the shapes and sizes 
most commonly used, but hand-presses are preferred at the smaller 
])lants, and are used at all plants for special, or infrequently used, 
shapes. Specially designed tunnel kilns are in successful operation at 
one or two plants. 

There has been a good market in California for rough-textured 
colored floor tile, and a number of small plants have been built to 
satisfy the demand. Most of these use a red-burning clay, or a 
mixture of bulf- and red-burning clays, with grog or siliceous sand. 
Hand molding in plaster molds is extensively practiced, but competition 
has led to the use of tile augers in many plants. If desired, an undu- 
lating surface can be imparted to machine-made tile by hand treatment 
before drying. Oil stains are frequently applied after firing to modify 
the surface color or lustre of the tile. The active demand for this 
class of ware in recent years has stimulated artistic development, and 
the product from nearly every plant possesses an individuality of 
design, texture, and color. In a few plants, however, slavish copying 
of successful designs from other plants was noted. 

Wall and fireplace tile: The artistic development of California 
decorative tile is an outstanding contribution to ceramic art in the 
United States. There is perhaps no other region in the world today 
that produces such a wide diversity of wall and fireplace tile, or that 
is so well prepared to create new designs for private homes, hotels, 
stores and office buildinus. Several factors have contributed to this 
condition, among which are the following: (1) An abundance of suit- 
able clays, cheap fuel and power, and low-unit labor costs which make 
it possiijle to produce certain types of tile so cheaply that they not 
only find an important local market, but can also be shipped to eastern 
])oints on a competitive basis. (2) An active state-wide building pro- 
gram that is based upon the necessity of providing for many new 
industries each vear and for new homes for the thousands of people 



CLAY RESOURCES AND CERAMIC INDUSTRY 29 

who annually enter the state from the east and middle west to become 
pennaiieiit residents of California. {'■]) The jirevailiii^- pi'osperity and 
resultant liijih standards of livinji' whieh are more apj)art'nt on the 
J*aeific Coast than in any other section of the United States. (4) The 
diversity of architectural design arising in part from the foregoing 
faetoi-s. and in i)art from the luitural environment of California, where 
climatic conditions favor out-of-door life throughout the year, and 
where comparatively low land values in most residential districts make 
it possible for a home builder to acquire sufScient land to avoid tlie 
necessity for a cramped architectural style such as must be used in 
more congested centers of population. The dominant motive of Cali- 
fornia architecture is Spanish-American, the keynote of Avhich is to 
be found in the missions that were establislied under Spanish rule in 
the latter part of the eighteenth and the first part of the nineteenth 
centuries. Suggestetl by this beginning the Spanish-Moorish, ^lexican- 
Aztee, and Pueblo Indian styles have been extensively used. Those 
desiring a relief from these types, yet desiring to build in keeping with 
their local surroundings, have often chosen Italian desigiis. Still 
others, desiring destinctive effects, and sensing the possible over- 
development of Latin types in many districts, have used New England 
colonial, southern colonial, English, Norman, and other types, many of 
which are hybrids or are indistinguishable as formal styles. 

Refractories: The manufacture of fire brick in California has now 
progressed to the point where practically all of the local demand for 
fireclay- brick and special shai)es is met by California products. Several 
manufacturers are making a fireclay brick with calcined clay grog that 
gives as good or better service as the best grades that are produced 
elsewhere in the United States. The demand for medium or low-duty 
fire brick is usually met by a (luartz-grogged fireclay product. One 
manufacturer is developing a flint fireclay brick. Another manufac- 
turer has been marketing a silica brick for the past two or three years. 
]\Iullite refractories are being manufactured at a plant in Los Angeles, 
using cyanite from a large deposit in the Imperial Valley desert. No 
commercial deposits of bauxite or diaspore have yet been discovered, so 
that the state is still dependent on eastern products where a diaspore 
brick is needed, as in linings for the hot zone of cement kilns. How- 
ever, sufficient ((uantities of bone clay have been found on several 
properties in southern California to permit its use as calcined grog 
and as a portion of the plastic content in the manufacture of high- 
alumina brick. 

The methods of manufacturing refractory ware in California follow 
the usual practices employed elsewhere. Most plants are equipped 
with auger machines for shaping the standard shapes. The better 
grades of brick are repressed. Some hand-molded standard brick are 
made, and are re])ressed in hand-operated presses. Special shapes are 
made bv hand-molding. Drving is nsuallv done in waste-heat tunnel 
driers, although a few humidity driers are in use, especially for the 
shapes that are difficult to dry. Round down-draft kilns are generally 
used for firing, and the firing temperature for most of the fireclay brick 
produced in the state is cone 11 (1325° C). One of the most notable 
developments is the use of a tunnel kiln by the Vitrefrax company for 
firing mnllite brick at cone 29 (1640° C). 



30 DIVISION OF MINES AND MINING 

Tableware: Plain and decorated .semi-vitreous table and hotel ware 
is made at a number of plants in California. Thus far, these ])lants 
have used imported clays, in conjunction with feldspar and silica from 
local sources. One ])lant, the Empire China Company, expects to j>o 
into production in tlie spring of 1928 on vitreous ware, using a Cali- 
fornia feldspar and silica and a Nevada china clay, together with a 
certain amount of Florida clay.'^ The manufacturing methods follow 
Well-established practice. 

Kitche7i ware and sionewarc: A number of potteries in California 
are nuuuifacturing kitchen ware antl stoneware. In most cases, all 
materials used in the body mix are obtained from local sources of 
supply. Slip clays for glazing have thus far been imported from 
other states. The usual manufacturing practices are followed. 

Art pottery: There are a few small potteries devoted to the produc- 
tion of distinctive lines of art pottery. As the type of body and the 
plant practice is different at each of these, the reader is referred to the 
check list, figure 1, and to the plant descriptions in Chapter III for 
further details. 

Red earthenware: The local demand for flower pots, ollas, earthen- 
ware household utensils and other red earthenware products is met by 
a number of plants, some of which specialize in one or more of these 
products. 

Sanitarij ware: A complete line of sanitary porcelain, with the excep- 
tion of bath tubs, is made at three plants in California by the casting 
process, using imported clays, California or Illinois silica, and Cali- 
fornia feldspar. All three plants are e([ui]iped with tunnel kilns for 
both the biscuit and glost firing. Biscuit firing is usuallv at cone 11 
(1325°C.), and the glost firing is at cone 6 (1230° C). 'Three metal 
enameling plants are devoted to the manufacture of enameled cast-iron 
sanitary ware. Semi-porcelain plumbing accessories are made at three 
smaller plants. One of these uses a body made entirely from California 
raw materials. 

Electrical insulators: The manufacture of high-tension electrical 
insulators probably presents one of the most difficult ceramic ]iroblems 
of modern industry. The industry is rppresented in California by one 
plant, that of the Westinghouse Electric and Manufacturing Comjiany, 
at Emeryville (c.v., p. 45). California feldspar is the only local 
material used in the body mix. Semi-])oi-celain electrical accessories are 
being made at three small plants in California. 

Thermal insulators: Although accurate statistics are unavailable for 
publication, the bulk of the diatomaceous earth insulating brick output 
of the United States, if not of the world, is produced in California. 
The Celite Products Company at Lompoc, and the Stockton Fire Brick 
Company at Stockton are the only producers at present. The produc- 
tion of sawn natural blocks of diatomaceous earth, at one time of 
importance, is now relatively small compared to the production of 
molded (hand or auger-machine) and fired shapes. 



'Personal communication from G. Ray Boggs, December 8, 1927. 



CLAY RESOURCES AND CERAMIC INDUSTRY 31 

STAT I ST J ('S. 
BRICK AND HOLLOW TILE. 

The briek and hollow tile statistics compiled by the State Division of 
Mines and Alining inelnde all classes of brick. The detailed figures of 
production and value for 1926, by counties and by class of ware, are 
given in Table 2. This is a com])anion to Table 6, referred to later 
under pottery clay, in which the segregated figures for other clay 
products are given. 

Table 3 gives statistics for the common brick industry of California, 
by y(>ars from 1896 to 1926 inclusive. The annual value of the com- 
mon brick production is plotted to a ratio .scale ou Tlate II. For com- 
parative purposes, Plate II also includes the curves for the average 
unit value of common brick per thousand, and the gross annual 
value and the average unit value per barrel for cement during the 
same period. The rapid growth of the cement industry relative to that 
of the common brick industry is of special interest, as is also the 
comparative trend of prices in the two industries. The trend of cement 
prices reflects the economies of steady technical and mechanical prog- 
ress in the cement industry, and the increasing size of plant units. The 
trend of common brick prices closely parallels the fluctuations in com- 
modity prices and labor wages, as modified by fluctuations in the unit 
cost of fuel, as a high percentage of the cost of making common brick 
arises from labor and fuel costs, and there have been no im])ortant 
technical or mechanical improvements in brick manufacture during 
the period under review. The influence of the San Francisco earth- 
quake of 1906 is strikingly shown by the decline of the common brick 
])roduction and the continued rise of the cement jn-oduction after a 
slight recession following the financial panic of 1907. 

POTTERY CLAY. 

The term 'pottery clay' as used in State Mining Bureau reports 
refers to all clay other than that used in the manufacture of common 
brick and liollow tilc.^ The production of pottery clay in California in 
1926 is given in Table 4, and the production by years, from 1887 to 
1926, inclusive, is given in Table 5. The production of pottery clay 
products in California during 1926 is given in Table 6. 

'For a further elaboration of this definition see Cal. State Min. Bur. Bulletin No. 
97, p. 94, 192(i, or other annual statistical reixirts Iiy the Bureau. 



82 



DIVISION OF MINES AXD MIXING 






2: S 
_l p ^ 

00 

< 



£ 2; 



I = 



fc 







-"^ CO ^ »c cri -J* c^i CD M ws c<i 00 


■^ 






CD<— <CO''»'t--O0'— 'OC-lTfr-OO »— « O—" ^J< 


OJ 






M*^ CO l'-^ ---<*•_ ■^_ CS^ Oi_ '<*' Ol or-* »0 00 C5 












t; 0^ 


'<*«'Tt'"cdiCeDc^rc>i'co'-f-':c'i>rr>r ^ irTco c{ 


CD 


CT 


3 


CO t-^ifJ'fl^COt^C'JO'— 'Ci Oi oco ^- 


<M 


II 




o_ 








«» 






CM ! 1 loo ! 


1 1 I.-H 1 1 I « 00 


cs 







M« 1 I .0 I 


■ 1 iCS . 1 . . ^ 


00 


"3 


CO [ J Ic<f I 

to , 1 , 03 , 


I . .C4 , 1 1 1 

I 1 ! ^ I I I ! c^i 


00^ 


■3^ 


> 


eo •-• 


III 1 I I 1 CO 


00 








c^ 


J3 J 












! !,-« I CD I I I I »o 


c^ 


Ss 





CO I ir^ 1 1 1 ■ 1 C4 


CO 




CO ' .Tf . '^ " ■ ■ 1 ,-1 


CO 

o' 


H 


CO ; ;<N ; I I I I CO 


Ci 






c^i I 1 ! 00 ! U3 I I I I 1 I 1 I 


»o 






ei • 1 < t-* > t^ i 1 1 1 1 1 1 .-H . 


00 


, 


a> 


(M, ,,,_,, .-III,,, 1 ,0 


W3 


-0— - 


3 


00' : I 1 o" ; -*" ! I I I ! ! I CD* 1 


00 





^C3 


•^^ ^0 CO . , to 


CO 


m-.C 


^^"5^1 "^ 


co_ 


O-C M 


K> 


«» 1 ; ; ; I I J I I ; ; i 




c..t:.S 






©& 


>> a 








_^ 


(N 1 I-rt* !^ III 1 IcO 1 


CO 


S c 


c 


Oai .t^'CO . 





C>2 


is 


eot .t^-t— 00 I 





CO > !^' ;co"* •III I lo" ; 


0" 




6 


: :^ 1 i I I i i" i 


CO 






t . ( r CD ■ 10 1 1 1 f 1 t (Ml 1 


CO 






Itli^H.COl'lll 1 Ol ■ 


»o 




0) 


. . . ico^ .r* 1 1 1 1 1 1 < 


0^ 










^ 


I I I 1 0* ! 00 I I I I I I »o I I 


•^ 




C3 


00 


00 




'■<*«, CO: I t* 







>- 


I 1 i 1^ 1 III!! I I I 




(D 






«^ 


Im 
















P^ 








-4^ 


• • .O't-* ■• iiOi 1 


^^ 




i^ 


.. it-,,.^ ,, lOOi ' 


00 




■ . lO'O '• itMi t 


CO 




I I * 1 1^' ! C5"» • • ! I I po I ! 


cT 




; ; 1 * , I I I '^ 1 1 


(M 




< 










> CO ^ CO Cti ■ '^ 01 10 (M 10 ' ' ' 


r- 






'^HCO-rfl-OO 'OC^-^CX)00 <-H 1 1 . 


os 







1 CO r- -- ic ■*_ 


en T)' crs i-^ t^ 10 II 1 


*o 












3 


; rt^'to'io'cOC^' 


00-* CO cor- TT ' 






S 


«©t^io^t^ 


r- c^ C5 C5 


CO 


c 


; 


•-' 1— 1 i-t .-t '^p , , 


<M 











CO 


a 








«» 


a 




















' CO r-- -r-i CO Cs» ^ Ci (M CD II 1 


'^ 


3_ 


i-f-ic^t^r^ ioc:>^co(>) r^ ■ i . 


CO 




. C-l i~« U3 Tj- <M QO C-1 C^ '^ (M CO ■ • 1 


CO 










1^ 


lO-rJ'OCO* OJ <0 00 -rji ' 


00 




C^ 111 


u 




<ji 












1 I I I ! « ! 0* ! IS 1 

: I : : ::h I g? 1 leg : 


















1 1 1 1 1 CO i.=* • 1 • 










; ; ; : ; s ;Q : : ; 










: : : : :^ : s : : s? ; 


















i i i i il :| ; ;g ; 










; ; ; 1 ;S :| ; jo ; 

i.itiHiOi'S, 










-r 1 cj 1 • a> • 










; ; : ; ; ;"= ; : a ; 










1 1 1 1 ."^ . u 1 5 ' 










— ■ ' s '*^ ' 

'^ ■ OM • 










; ; ; ; I'E IX. M . 










s 1 . I.H 




a 







: ; ; : ;3 is i^-g ; 

i i i i il if i"is i 

i i i i il^l i^fg 

III \m 
i i i i ii^i \m 


































'. 1 1 1 1 t." 0" tT 1 8 2 3 










' ' § • aO a'^ =«-2r-n 

li-|il--3:-|355 
















i i i is : 








^3£:«52>«c55 5-2^ ^^ ^ ^'^ 








<p3;=.;ij^o;i^ 


c«ccaia:aj< < CO 








■^ S 



c- 

o tc O 

g-2 3 

o " S 

Iss 

.S-OT3 

a s s 

o c c 



33 



A.V. value 


per M 


$6.11 


5.74 


5.54 


6.18 


5.83 


6.44 


7.14 


7.35 


7,18 


6.90 


7.05 


7.32 


6.74 


6.33 


6.05 


6.08 


6.28 


5.75 


6.13 


6.12 


6.56 


7.14 


9.43 


12.18 


17.24 


14.21 


13.48 


13.03 


12.30 


11.12 


9.82 


'al. State 



3f 

1 roofing 

ay prod- 
refracto- 
tile, and 

e r pipe, 

duit, red 
, faience, 
nd sewer 



factories, 

ous. 

!y, sewer 

ind roof- 

henware, 

hen ware, 
arious. 



nee, floor 



1 e y and 
tile. 



32 



DIVISION OF MINES AND MINING 



O C-. 



o 



esi — o 

Z S -" 
S £ ^ 



» E 



o 
X 













■^50 ^OiOOi OO'* W COM lO MO 00 


■^ 






CDi— tCO'^t-00'— •C3C'l^*<r--00 »-« ^1— « ^*< 


M 






M'^coi'-_»--^^-«r Ci_c?;^'rr 3iOr^__ »0 O^O cs 












C5 


w 


■^ -a- eO lO eoc^l C>f Oo"'^'tC l^'l-*" Tt^* icTo CI 


CO 


3 


CO t-^»OM'i^cot^Mc:'— "OS Oi oc2 — 


C^ 


1' 


> 


** CO 


o 






C4 I I !oo ! 


1 1 > T-< t . 1 1 DO 


Ci 


.E "1 

•3^ 


O 


^ ■ r .O I 


1 1 .0> 1 I , , ^ 


OO 


J 
> 


"2 1 Oi 


1 1 ■ C^ 1 1 1 . Ci 

I I !<=>' I I I I c-i" 


OO^ 


<^ ^-• 


III 1 1 I I CO 


00 




^'^ I I 1 I 




t/> 


1° 












O ' . ^H 1 CO . . . 1 »0 


M 


-2-S 


C 

o 


CO 1 il^ . O ' 1 1 • <N 


CO 




»f5" ' # 1 ^ ' » » • • ' ' ' ' CO 


CO 

o' 


H 


<^ ■ .c^ I ; ; ; ; CQ 


Oi 






<M 1 1 ■ GO ' »C - ' t 1 1 . I O ! 


iO 






M 1 1 ■ r- 1 r^ 1 1 .— 1 t 


OO 


. 


o 


M 1 1 . ^ 1 1-H t 1 . ( . . , o ' 


"3 


■o-o" 


3 


Qo I ! ; o" ; M** I I I I ; ; ; co' i 


oo" 


<u >< 


^« 


f^ "^ . f^ . ■ «= 


CO 




^*^^. ■^ 


co_ 


H-* 


«» ! I ; ; I 1 I r I I I I 




c..ti.S 






So 


. > > 

u >>C. 








^ 


M I !tj* 1,1 ! ! ! I Ico I 


CO 


a c 


C3 


0>i it^'CO iir 1 lO I 


C3 


5^ 


2^ 


CO_ I 't^. "~^ III . .(» . 

CO I • I '-<" I CO * » I I I I I o I 


o 
o' 




s 


\ :^ : ; ; : : r ; 


CO 






1 1 1 . CO " tr> 1 1 1 1 1 1 Ml 1 


CO 






1 . 1 .w .CO < ' t • p I O I . 


u:) 




O) 


ttiiCO't^ O * 1 


o_ 




3 


I I I ! o' ! oo~ I ! J I ! I »o" I I 


-*" 




J^ 


00 !^ o 


oo 




M^.CO t^ 


lO 




K* 


; ; ; ;&^ ; I I I I I I I I 




s 




• 111 1 t > 1 1 1 1 1 ■ 


^ 










hi 








-u 


II lo II^ I '< I ifD I I 


,_, 




c 


■ r . t-- 1 ■^ .1 1 OO 1 1 


oo 




:3 


' i 1 O 1 O t ' ' C^ 1 t 


CO 




'^'S 


II* 1 1^' I cT* * • ; ' ; eo' I ! 


Oi 




S 


I 1*1 It 1 '^ 1 1 


CM 




<I 










1 co^ ocoo 


O '* M »r> C^ lO II 1 


t^ 






. ^^co-* r^ OO 


OC^ -* OOOO i-H 11 « 


05 




(U 


1 CO r^ 1— lO -^^ 


C5 -^ 05 1-^ r^ »o 1 " 1 


to 




3 


! -^'co'io co'm 


oo'-^'co'co'r--" •^"" I 1 I 


i—T 






6©t^iO'-«r^ 


t-MO CI O 


CO 


c 
o 


I 05_ 


^i^H ^ r-l ^rS* 


M 

co" 


a 








09 


a 
















O 




•COr-.'-HMM 0'-«ClOM CO II 1 


-^ 


g^ 


. 1^ 1-. Ci t^ t^ <0 O to CO M I^ » 1 ' 


CO 




. M '-1 »0 -rf M OO <M M -^ <M GO i 1 i 


CO 










1^ 


; lo'Vcrso"* Mo'co' oo' mT I I I 


00 




, C<1 III 


C-1 

CO 




< 












I I I I I «j" I o" 1 19 I 










I 1 1 : i:h I g" : icQ : 

1 1 1 1 1 00 '.S 1 1 1 










: ; : : ; s ;q ; ; o ; 










; : : : ;^ ; « ; ; Sf ; 


















:;;;;■§ ;o- ; ;o : 










i i i i ife il i ;» i 










; ; ; : ;S : a ; ; o ; 




















iiiiiaiuiigi 




















I I '. I 'r'§ Ice I I a I 










i ; ; i ;s ife ; il : 










: ; : : ; «" :J '.^S : 










1 1 ; 1 ','C ;&< ; M . 










a ' " ■ M ' 




>. 






1 1 1 1 <JZ 1 u I c ^ ■ 

i i i i i4 i| i^.> i 




a 
o 
O 






; i i i :"iii;|l; 
: i i i i«ll iirs 


















; ; ; ; ;-2=-S :co-a3 




























o " o ' „- ° O 


















' ' ' ' ' I." o" I." ' S £i 3 

; ; ; o ao ,e;£kj 










! ! 1 ,-c.2-c» t^ - 
















i i i is : ■ 


^5^ rt rf « 3 «^ C 2 2 S^ 


-2 

1 






rt-tiSt?99rt>«GCc:c:o302rtM«*r^ 








-ii 3 I- G^ o »-•— • 







PLATK U 







« A ^ 


50 
40 

30 
20 

lb 

e 

5 
4 

3 

1 ^ 
1 , 

>. 0.9 

1 §^ 
,« , . 06 

It 

lo .10 

^ k 05 
















































X.. 












20 H^ fi 

1 1 
•4 ^5 S 

II 

^^ 

«J jo 














































.''' 






'^*^ 


— 


^^^^ 














































'■ 






























Aret 


■acre 


Price 


0^ 


Corrrn 


ion t 


rick 


//7 ^J 


ilan^ 


per 


fpoi/s7na~^ 






••^ 






























^^ 










•m.^ 














1 \ 




•"^ 


























^^ 

















-.^« 


^_i 





^_ 


__ 




-J4- 


'" 






























1 












































































































^ 






































































\, 


































^ 


— 


k J 




— ■ 
















\ 


' 


Avei 


-a^e 


°rice 


of C 


emer. 


f in i 


io//>^r6 


per 

\ 


barn 


r^. 

\ 






^ 




/ 


^ 




/ 


























































/ 










































^^ 


•v. 














































Ann 


ua/ \ 


'firliJe 


0^ 


Zemi 


'nt-\ 




S. 




^^._^ 




















































~7 




S 




^^'**- 


-^....^ 


















































/ 


























1 






























J 


























k' 


"-. 






























/ 


























• 
• 






"-x^ 

























^ 


»r^"** 


/ 






V-- 














/ 










An, 


7ua/ 


Va/ue 


of 1. 

■ a 


'omn' 
'r/ck 


7on 


-''' 










> 


'-'' 


**"""• 


-—-"—' 


^^' 


^*fc 










y**-A/ '/7L/Cf/ 
/ 

/ 


Vcfiui ' of 'omr, 70/7 I ^nck 












































SI/ 








1 














r' 




/ 




















































,' 


'•^.^ 


y 




/ 




















































,'■ 








/ 




























































/ 
















































^^' 












A- 


Anm 


•a/ ^a 


/i/e 0. 


■^ Ce. 


nenf 
















































/ 




























































/ 




















COMMON BRIC 


Kand CEI^ 


ENT 












/ 




\ 


y 


/ 




















STATISTICS OF CALIFORNIA 
1896 TO 1926'' INCLUSIVE 












7^ 












































, 














/ 


























































t 
























































































































1^.03 
0? 






























































/ 
























































































































1896 97 98 99 1900 01 02 03 04 05 06 07 08 09 1910 11 12 13 \A 15 16 17 18 19 1930 21 22 23 34 -25 26 1 



i\'i\-i — rui-iMK iiiiy./ :;;; 



32 



o 



to" £ 

CM t- 



z 


U 


T-1 


UJ 


3 


c 


CO 

< 


£ 

0. 


z; 


1- 


9 


.^ 










1- 


0; 




i 






_o 


3 




"5 


W 




I 


^ 




•o 


c 




c 


o 




a 


^ 




^ 


fc 



1 



(LAV IJKSOURCES AM) CKUA.MK' IXDUSTKV 



3;] 



TABLE No. 3. 

Common Brick Production of California, by Years.* 

Production Av. value 

Year M Value per M 

ISyb 74,240 $391,567 ?6.H 

1897 88.890 509,955 5.74 

1898 108,076 598,823 5.54 

1899 : 129,512 800,210 6.18 

1900 119,906 698,583 5.83 

1901 146,522 943,250 6.44 

1902 181,040 1,291,941 7.14 

19U3 217,715 1,600,882 7.35 

1904 256,898 1,843,936 7,18 

1905 284,205 1,961,909 6.90 

1906 278,780 1,962,866 7.05 

1907 339,439 2,483,062 7.32 

1908 236,383 1,593,814 6.74 

1909 276,396 1.749,209 6.33 

1910 280,265 1,694,312 6.05 

1911 282,199 1,716,442 6.08 

1912 349,797 2,198,303 6.28 

1913 295,729 1,699,426 5.75 

1914 221,243 1,356,885 6.13 

1915 160,452 981,888 6.12 

1916 168,826 1,107,940 6.56 

1917 169,045 1,207,765 7.14 

i:tl8 96,732 912,205 9.43 

i:tl9 126,892 1,545,558 12.18 

l;(20 163,782 2,823,304 17.24 

1921 202,417 2,880,124 14.21 

1922 323,625 4,363,629 13.48 

1923 397,754 5,194.527 13.03 

1924 335,203 4,124,385 12.30 

1925 297,449 3,317,766 11.12 

1926 328,664 3,231,597 9.82 

•Data prior to 1920 from U. S. Geol. Surv. Min. Res., since 1920 from Cal. State 
Min. Bui'can repf>rts. 

TABLE No. 4. 

Production of Pottery Clay in California in 1926. 

(From State Div. Mines and Mg. Bulletin No. 100, p. 97, 1927.) 

Ciiunty Tons Value Used in the manufacture of 

Alani(_-da 5,870 $7,183 Drain, faience, flood, quarry and roofing 

tile, sewer pipe. 

.A.mador 97,768 135,767 Architectural terra cotta, fire clay prod- 

ucts, chimney and sewer pipe, refracto- 
ries, drain, floor and roofing tile, and 
various. 

Ciiniia Costa 7,675 5,688 Architectural terra cotta, sewer pipe, 

faience and drain tile. 

Los Angeles a86,767 99,076 Architectural terra cotta, conduit, red 

earthenware, refractories, drain, faience, 
floor and roofing tile, chimney and sewer 
pipe, and oil well mudding. 

Monterey 491 1,164 Floor and roofing tile. 

Orange 13,150 38,989 Conduit pipe and stoneware, refractories, 

di-ain and roofing tile, and various. 

Placer 104,250 147,241 Arcliitectural terra cotta, chimney, .sewer 

and conduit pipe, drain,, floor and rf)of- 
ing tile, sanitary ware, red earthenware, 
and various. 

Jliverside 58,528 > 178,383 Conduit and sewer pipe, red earthenware, 

refractories, roofing tile, and various. 

.'^acramento 1,548 2,310 Crushed brick, faience tile, et al. 

San IJernardino __ ''2,268 10,605 Porcelain. 

San Diego '•130,187 58,269 Therapeutic clay, sewer pipe, faience, floor 

and roofing tile, and various. 

Santa Barbara ___ 1,100 1,700 Drain, floor and roofing tile. 

Ventura "373,000 93,250 Oil-well drilling mud. 

Butte, Calaveras, 
Humboldt, Mer- 
ced. San Luis 
Obispo, Santa 
Clara, Sonoma"* 18,859 26,884 Earthenware, porcelain, chimney and 

„ sewer pipe, drain and roofing tile. 

Totals 801,461 $806,509 

* Combined to conceal output of a single operator in each. 
=> Includes clay and shale for oil-well drilling mud. 

'' Includes kaolin. 

"■ Includes 'Cornwall' stone. 

* Includes therapeutic clay. 

3 — 54979 



34 DIVISION' OF MIXES AXD :MIXIX0 

TABLE No. 5 

Pottery Clay Production of California, by Years. 

(From Slate Div. Mines and Mg. Bulletin Xo. 100, i>. 98, 1927.) 

Year Tons Value Vear Tons Value 

1887 75,000 $37,500 i:i07 160,385 $254,454 

1888 75,000 37,500 IKOS 208,042 325,147 

1889 75,000 37,500 1909 299,424 4G5,647 

1890 100,000 50,000 1910 249,028 324,099 

1891 100,000 50,000 1911 224,756 252,759 

1892 100,000 50,000 1912 199.605 215,683 

1893 24,856 67,284 1913 231,179 261,273 

1894 28,475 35,073 1914 179,948 167,552 

1895 37,660 39,685 1915 157.866 133,724 

1896 41,907 62,900 1916 134,636 146,538 

1897 24,592 30,290 1917 166.298 154,602 

1898 28,947 33,747 1918 112,423 166,788 

1899 40,600 42.700 1919 135,708 245,019 

1900 59,636 60,956 1920 203,997 440,689 

1901 55,679 39,144 1921 225,120 362,172 

1902 67,933 74,163 1922 277,232 473,184 

1903 90,972 99,907 1923 376,863 697,841 

1904 84,149 81,952 1924 417,928 651,857 

1905 133,805 130,146 1925 537,587 674.376 

1906 167,267 162,283 1926 801,461 806,509 



Totals 6.710.784 $8,442,643 

TABLE No. 6. 

Value of Pottery Clay Products Made in California During 1926. 

(From State Div. Mines and Mg. Bulletin Xo. 100, p. 97, 1927.) 

X-imber of 
Product p.oducers Tons Value 

Architectural terra cotta 5 15,954 $2,361,524 

Chimney pipe, terra cotta and flue lining 10 13,207 461,786 

Drain tile 12 7.17S 113.168 

Roofing tile 21 73.9S4 1.917,415 

Sewer pipe 10 100.689 2.910,567 

Ohinaware and semi-vitreous tableware 3 627,516 

Sanitary ware 6 1,894.705 

Red earthenware 6 198,308 

Stoneware and chemical stoneware 6 434,772 

Floor, faience, mantel, glazed and hand-made tile 27 2,867,772 

Miscellaneous art pottery, bisque ware, brick dust, 

calcined clay, ceramic, mosaic wall tiles, conduit, 

conduit pipe, fire clay products, crushed brick and 

tile, garden furniture and pottery, high temperaturt- 

cement, porcelain, gas radiants, and backs, cast 

stone, ground clay, fire clay and grog, broken tile 

and various 23 837.670 



$14,625,203 



CLAY RESOURCES AND CERAMIC INDUSTRY 35 



TOTAL ANNUAL VALUE OF CLAY PRODUCTS IN CALIFORNIA COM- 
PARED TO THE TOTAL FOR THE UNITED STATES. 

The figureis of the annual value of clay products, and the number of 
producers reporting are given in Table 7, for California and for the 
entire United States during the period from 1896 to 1926. inclusive. The 
ranking of California auu)ng the states, and the production of Cali- 
fornia as a percentage of the total United States production are also 
shown in the table. The production tigures are i)lotted on a ratio scale 
on Plate 111. Both the California and tlie United States curves may be 
conveniently divided into four time periods: (1) From 1896 to 1907, 
a period of rapid growth, during Avhich the United States ])roduction 
increased at an average of 8.7 per cent per year, whereas the California 
l)roduction increased at an average of 21.3 per cent per year. (2) 
From 1907 to 1915, a period of dei)ression following the financial panic 
of 1907, the effect of which was exaggerated in its influence on the 
common brick and hollow tile industry of California by the San Fran- 
cisco earthcjuake of April, 1906. During this period the average 
annual production of clay products in the United States remained 
nearlv stationary, while that of California showed an average annual 
decrease of 5.7 per cent. A contributing factor to this condition, both 
in California and in the United States at large, was the ra])id increase 
in the use of reinforced concrete, especially in the construction of large 
buildings in the major cities. (3) From 1915 to 1923, a period of 
rajiid expansion and rising. prices, but with a retardation of growth in 
1917 and 1918 in the ])roduction of certain ceramic branches, such as 
architectural terra cotta, which were classed as nonessential and were 
unable to secure sufficient fuel or labor for maximum production, and 
a further period of retardation in 1921, following the post-war deflation 
that gained momentum in 1920. The latter effect is not noticed in the 
ceramic production of California. The average annual increase in the 
value of ceramic products in the United States during the eight year 
period was 12.7 per cent compared to 24.6 per cent for California. (4) 
From 1923 to 1926. Tlu' {)eriod is too short to permit accurate interpre- 
tation of trend, but a slowing down is apparent, both in California and 
in the United States at large. 

The average annual rate of growth of the value of ceramic products 
in the United States for the entire period of 30 years from 1896 to 
1926 was 6.0 per cent, compared to 12.3 per cent for California. 



no 



DIVISION OF MINES AND MINING 



TABLE No. 7. 

California and Total United States Production of Ceramic Products 

from 1896 to 1926.* 

California United States 

No. Raik 'U uf Number 

of i>r(>- anijnji total of 

Years Value ducers states l^. S. value Value producers 

1S9C $680,207 91 21 1.08 $6;',, 110, 408 629,3 

1897 703,410 92 21 1.13 62,359,991 5424 

1898 1,263,734 77 12 1.70 74,487,680 5971 

1899 1,587,518 79 12 1.66 95,797,370 6962 

1900 1,375,998 72 14 1.43 96,212,345 G375 

1901 1,769,155 92 11 1.61 110,211,587 6421 

1902 2,253,096 89 11 1.84 122,169,531 6045 

1!I03 2,831,543 105 9 -2.16 131,062,421 6034 

i:t04 3,624,734 121 8 2.77 131,023,248 6108 

191)5 3,865,147 122 8 2.58 149,697,188 5925 

1906 4,364,230 113 8 2.71 161,032,722 5857 

1907 5,740,537 118 8 3.61 158,942,369 5536 

1908 4,523,745 119 8 3.40 133,197,762 5328 

1909 4,437,165 99 9 2.67 166,321,213 5068 

1910 4,842,391 107 9 2.85 170,115,974 4915 

lilll 4,915,866 92 8 3.03 162,236,181 4628 

1112 5,912,450 91 8 3.42 172,811,275 4284 

1913 5,344,958 91 9 2.95 181,289,132 4065 

1914 4,461,661 84 10 2.70 164,986,983 3860 

1915 3,599,375 83 10 2.21 163,120,232 3636 

1916 4,163,426 79 10 2.01 207,260,091 3412 

1917 4,826,125 74 11 2.10 232,512,773 3153 

11)18 4,329,220 68 11 2.00 221,884,651 2783 

1919 5,834,648 66 10 2.10 275,346,378 2776 

1920 10,946,423 65 9 2.9 373,670,102 271G 

l!)21 11,172,491 63 8 4.1 270,738,536 2449 

1>)22 14,689,830 62 6 4.6 321.494,403 2098 

1923 20,833,053 86 6 4.9 424,582,628 2441 

1924 20,994,732 86 (i 5.0 415,779,378 2353 

1925 21,324,844 99 6 5.0 423,446,917 2417 

1926 21,651,327 95 _ 4.6 459,049,470 2391 

* Prom U. R. Geol. Survey prior to 1920. Since 1920 from U. S. Bur. Mines, Min. 
Res. 



CLAY RESOURCES AND CERAMIC INDUSTRY 



37 



Eh 

<: 



SdVllOQ JO SNOnilW 



o o 
o o 

iC 



o 



— cfddd 




It) § 



o 
o 



o 
o 



ooooo o 






9bviioa JO 



SNioniiw 



38 DIVISION OF MINES AND MINING 

Chapter III. 
CLAY DEPOSITS AND CERAMIC PLANTS BY COUNTIES. 



ALAMEDA COUNTY. 
General Features. 

Alameda County is on the eastern shore of San Francisco Bay and 
has a land area of 732 square miles, 500 of which are ricli agricultural 
bottom lands devoted to farmini>- and fruit growing-. The princijial 
cities are Oakland, Alameda and Berkeley. The population of the 
county is 344,177 (1920 census). 

The county is traversed in a northwesterly and southeasterly direc- 
tion by several mountain ranges, which together form the eastern grouj) 
of the Coast Range mountains. These ranges become rugged and reach 
higher altitudes in the southeastern portion of the county, their con- 
tinuation into Santa Clara County culminating in the ]Mount Hamilton 
range. The mountains consist largely of metamorphic sandstones, 
jaspers and serpentines of the Franciscan formation, together with 
sandstones and shales of Cretaceous and Tertiary age. 

The mineral resources of Alameda County include asbestos, brick, 
chromite, clay, coal, limestone, magnesite, manganese, potash, pyrite, 
salt, soapstone, and crushed rock, sand and gravel. The principal com- 
mercial mineral products in the order of their relative importance are : 
miscellaneous stone, salt, brick and hollow tile. 

Clay Resources. 

There are excellent deposits of common clay suitable for the manu- 
facture of common brick, hollow tile, and roofing tile at various places 
in the county, and a number of i)lants for manufacturing these products 
are in operation. The best and most extensive common clay deposits 
occur in the Livermore and Niles valleys. 

High-grade clays were at one time mined near Tesla, on the eastern 
edge of the county, but there is no present production. 

On account of favorable manufacturing and marketing conditions, 
a number of important ceramic plants have been established in the 
county, especially in Oakland, Alameda, Berkeley, Niles and Livermore, 
and a wide diversity of ceramic ware is produced. 

California Bisque Doll Companii. Mrs. H. T. Epperson, manager. 
Office and plant at 1175 San Pablo Avenue, Berkeley. Formerly the 
California China Company. This plant was built in 1906 for the 
manufacture of bisque doll heads, but there was no commercial output 
until 1919. It is said to be the only plant in the TTnited States produc- 
ing bisque doll heads on a commercial scale. A number of other ceramic 
products are made, such as salt and pepper shakers, art vases and bowls, 
and novelties. California raw materials are used whenever possible. 
The use of Clark and IMarsh kaolin from near Cali.stoga (samples No. 
] 90-192, pp. 261, 280) is of special interest. The clays are prepared by 
small scale apparatus, and most of the shapes are made by casting. 



CLAY RESOURCES AND CERAMIC INDUSTRY 39 

Fii"iii^' is (lone in safrgors in a small np-di'ai't kiln, firetl to cone 12 for 
biscuit ware, and to cone 7 to [) for the g:lost firin<r. 

Bibl: Cal. State Min. P.nr. Prel. Ropt. No. 7, |). 35 (California 
China Company). 

California Faience Company (formerly The Tile Shop). C. 1\. 
Thomas and "W. B. Brap-don. owners and operators, 133") Hearst 
Avenue. Berkeley. At this ])laiit. jilazed art pottery, art tile, and 
inserts are made from a re(l-l)ui'nin<i: body, the composition of which 
\aries from time to tinu% depeiulin<i' upon the clays that are available. 
Shale is purchased from the Riehmoiid Pressed Brick Co. (sample No. 
110, ]). 325), and clay is somelimes obtaiiu'd from the Angel Ranch 
deposit near Eureka (sam])le No. ISl, p. 336). 

The clays are prepared by ball-millinpf, and are pup:j2:ed by hand. 
IMost of tlie art pottery is shapped by castinfj, and the tile and decoi-a- 
tive inserts are made by hand ]iressing in plaster molds. A p:as-fired 
pie-bakinp: oven is used to finish the dryinp:, after air-dryinj; is com- 
])leted in the shop. 

Two hilns are in use. One is a Calkins kiln, and the other is a round 
down-draft kiln, 13-ft. in diameter and lO-ft. high, wdth a continuous 
bag-wall extending nearly to the crown. The biscuit and glaze firing 
are done together, the kilns being set so that the w^are to be biscuited 
receives the greater heat. Cone 04 is brought down in the biscuit 
zone of the kilns. 

The company has been successful in establishing a small, but high- 
cla.ss market for its ware, and a considerable part of its output is 
shipped to Eastern points. Special orders are taken for ornamental 
garden and fountain pieces, as well as for pottery and tile. 

Two or three men are employed in addition to the owners. 

Bibl : Cal. State :\rin. Bur. Prel. Rept. No. 7, p. 37. 

California Pottery Company. P. A. Costello, president ; J. P. Cree- 
gan, secretary. Plant, 2265 East Twelfth Street, Oakland. (The com- 
pany also o]ierates a ])lant at ^Merced, see ])age 12S.) This company was 
established in 1872. The products made at this factory are vitrified 
sewer pipe, chimney pipe, flue lining, garden pottery, lead pots for 
Ihe paint industi-y, wall and floor tile (faience), roof tile, and stone- 
ware. Th(> clays used are Lincoln No. 1-6 (sami)le No. 146. p. 303), 
lone sand (Shepard) (sample No. 128, p. 261), Valley Springs clay 
(samples No. 202-204, pp. 299, 337), a surface clay from Niles, similar 
1o that used by the Niles plant of the W. S. Dickey Clay Manufacturing 
<'(). (sam])le No. 265, p. 343), and some Nigger Ilill clav from Calaveras 
County (sample No. 236, p. 263). 

The sewer pipe, chimney pipe, flue lining and garden pottery and 
1 ile mixtures are prepared by dry-pan grinding, followed by wet-pan 
pugging. Sewer pipe is made in the usual presses. Chimney pipe, 
flue lining, and roofing tile are also made in a sewer-pipe press. Some 
of the roofing tile are hand finished, giving the appearance of hand- 
made tile. Floor tile, wall tile, and garden pottery are hand molded. 
Single-fire glazes are used. 

The clay mixture for stoneware is prepared by blunging, filter press- 
ing and pugging, followed by ageing for a suitable period. Most of 
the stoneware is jiggered. 



40 DIVISION OF MINES AND MINING 

Diying is done iii a steam rack for the tile and stoueware, and other 
ware is dried on floors heated with waste heat from the kilns. 

Eight round down-draft kilns are used, fired with oil, atomized with 
steam. Two or three are 30-ft., four are 28-ft. and two are 25-ft. in 
diameter. Stoneware is fired to cone 8 (2400° F. on pyrometer) and 
other ware is fired to 2100° F. The average firing time is four days, 
making the total cycle 8 to 9 days per kibi. Sixty men are employed. 

In 1927, this company purchased the property formerly operated by 
the California Pressed Brick Company, and the plant was overhauled 
and newly equipped for the manufacture of brick and tile.^ 

Bibl : Cal. State Min. Bur., Bull. No. 38, p. 202 ; Prel. Kept. No. 
7, p. 36. 

N. Clark and Sons. A. V. Clark, president and general manager ; G. 
D. Clark, secretary. Main office at 112-116 Natoma Street, San Fran- 
cisco. Plant at Pacific Avenue and Fourth Street, Alameda. This 
plant has been in operation since 1889. The principal products are 
architectural terra cotta, sewer pipe, fire brick and face brick. 

The company owns or controls deposits of all raw materials used in 
the body mixes at the plant. Sand and clay from lone (see under 
Amador County) and a calcareous shale from a deposit at Walnut 
Creek (see under Contra Costa County) are the principal materials 
used. 

The fire brick and face brick are made by the stiff-mud process, 
without repressing. Sewer pipe and terra cotta are made by the usual 
processes. Sixteen oil-fired round down-draft and muffle kilns are 
in use. 

Part of the plant was destroyed by fire in July, 1917, but was rebuilt 
in 1919. Another fire occurred on September 16, 1927, which caused a 
shut-down during reconstruction. 

Bibl : State Min. Bur. Bull. 38, p. 202 ; Prel. Kept. 7, p. 36. 

W. S. Dickey Clay Manufacturing Company: N. A. Dickey, manager. 
Office, 604 Mission Street, San Francisco. Plant No. 18 is one mile west 
of Niles, and was formerly known as the California Brick Company. 
Hollow tile and paving brick are manufactured. A Haigh continu- 
ous kiln is used for firing. Plant No. 19 is at Livermore, and was for- 
merly known as the Livermore Firebrick Works. Fire brick, fireclay 
refractories, face brick and sewer brick are manufactured. 

The management refused permission to publish data on the two 
plants, and as much of the data previously published by the Bureau is 
obsolete, there is no need for repeating it here. 

Bibl: Cal. State Min. Bur. Prel. Kept. No. 7. p. 35 (California 
Brick Company), and p. 37 (Livermore Firebrick Works). 

ElectHcal Porcelain Works. Levi S. Baker, proprietor; Joseph Baker 
and Chas. Ball, officials. Office and plant at 2414-16 Sixth Street, 
Berkeley. Electrical porcelain insulating products are manufactured, 
using English china and ball clays, Florida kaolin, San Diego County 
feldspar and silica, and lone and Lincoln fireclays. The ware is 
shaped by dry pressing, throwing, turning, machine-pressing, or cast- 
ing, according to the nature of the shapes to be made. Two oil-fired 

' Clay -Worker, July, 1927, p. 36. 



CLAY RESOURCES AND CERAMIC INDUSTRY 41 

kiln.s are used. One is 14 feet in diameter, and tlie other is 8 by 8 feet 
square. 

Hidecker Tile Company. G. C. liidecker, manager. The plant is 
at Twenty-fourth and Union streets, Oaldand, and manufactures roof- 
ing tile only. Local clay from excavations in Oakland and vicinity 
is mixed with Lincoln chiy (samjile No. 147, p. ;]03) and Natoma clay 
(samples No. 210 and 212, p. 337). A Williams hammer pulverizer is 
u.sed to disintegrate the clay, which is then screened through an 8-mesh 
screen, passed to a pug-mill, and finally to an auger machine, which 
is equipped Avith a hand-operated wire-cutter. The tile are dried on 
pallets in the open air. 

Two up-draft oil-fired kilns are used. The larger of these holds 
25,000 eighteen-inch tile, and the smaller holds 12,000 tile. The water 
smoking is done with wood-shavings and requires 24 hours. This is 
followed by four days firing with oil, to a finishing temperature ranging 
from 875° to 980° C. Plight to ten men are employed during the 
operating season of five to eight months. 

Kraft Tile Company. A. Clay Myers, in-esident; J. L. Kraft, C. H. 
Kraft, E. Ridgeway, and II. E. Leash, directors and officers. General 
office, 55 New ^Montgomery Street, San Francisco. Plant at Pabrico, 
two miles west of Niles. 

This plant was built in 1926 to manufacture high-fired faience tile, 
using Lincoln fireclay and lone sand. Augers are used for shaping the 
tile. Hot-air driers of the deliydrator tyi)e are used for drying. 
After drying, the tile are carefully trimmed to size in a special machine 
before applying the glazes. This produces a finished tile that falls 
within closer limits of size than is customary in most plants. The 
product is fired in round down-draft kilns. The output of the plant 
in July, 1927, was 1000 square feet of tile daily. 

Miller's OaMand Art Pottery. ]\Irs. Isabelle Miller Burress, owner. 
Albert Van Cleve, manager, 2237 East Twelfth Street, Oakland. Sewer 
pipe, patent chimney pipe, flue lining, and drain tile are made at this 
])lant. Yarn and Harvey clays (sam]>les No. 124 and 133, pp. 298, 302) 
from M. J. Bacon, lone, are used, together with excavation debris from 
Oakland and vicinity. 

The clays are prepared in dry and wet pans, and the ware is shaped 
in steam presses. Drying is done on the floors of the building, without 
special provision for heating by waste kiln gases. 

The firing equipment consists of five oil-fired round doAvn-draft kilns, 
the largest of which are 22-ft. in diameter and hold 35 tons of ware. 
The firing schedule varies from 48 to 72 hours, depending on the ware, 
and the finishinc- temperature averages 2000° P. (1093° C.) with a 
maximum of 2100° F. (1149° C). 

Twenty-five men are employed. 

Bibl: Cal. State Min. Bur., Bull. No. 38, p. 204 (Oakland Art 

Pottery). 

M & S Tile Company. Owned by F. J. Thomas, G. L. Smith and 
J. ]\I. Bettencourt. The plant is near the Oakland-Niles highway at 
Decoto. This plant was established in February, 1926, for the manu- 
facture of hand-made roofing tile. A local surface clay (sample No, 



42 DIVISION OF MINES AND MINING 

264, ]x 848) is used. Tlie clay is similar to that used in the W. S. 
Dickey Company's hollow tile i)lant at Xiles (sample Xo. 265, j). 843). 

The clay is mined -with the aid of a team and scraper. A small power- 
driven pug-mill prepares the clay for hand-molding. Drying is done 
on pallets under a shed. A rectangular oil-fired down-draft kiln, having 
a capacity of 5700 roofing tile, is used for firing. The firing schedule 
occupies 55 to 60 hours, and the finishing temperature is cone 06 
(1005° C). 

Five men were employed at the time of visit, in September, 1926. 

Muresque Tiles, Inc. Wm. P. Muir, president and manager; Chas. 
Orpin, secretary; 1001 Twenty-second Avenue, Oakland. This is a 
small plant for making hand-pressed floor, wall and mantel tile, and 
decorative inserts. Lincoln and lone clays are used, which produce a 
buff or cream body. Matt glazes are used, which are buffed on a 
wheel after firing, producing effects similar to the well-known 
Batchelder tile, made in Los Angeles (see page 97). An oil-fired 
muffle kiln is used. No further details would be furnished by the 
company. 

RemiJUird Bn'cJi Company. C. Remillard, president; R. C. Giroux, 
secretary. Office, 332 Phelan Building, San Francisco. The plant is 
one and one-half miles northeast of Pleasanton, on the main line of the 
Southern Pacific Railroad. The plant was established in 1889 and has 
been oi)erate(l continuously since then. Common red brick are manu- 
factured. 

The clay deposit consists of a sandy loam, 25 feet thick, and is mined 
from a pit one-(iuarter mile from the plant by a drag-line scra])er oper- 
ated by an electric hoist. The clay is loaded into cars and hauled by 
motor to the i)lant. The soft-mud process is used. The brick are dried 
under sheds in the yard, and are fired in two 16-compartment Hoffman 
kilns, of 20. 000 daily capacity each. Fifty men are employed during 
the season. 

Bibl: Cal. State Min. Bur. Repts. XII. p. 381; XIII. p. 613; Bull. 
38, p. 242 ; and Prel. Rept. No. 7, p. 37. 

Teclinkal Porcelain and China Ware Company. J. Pagliero, owner. 
Office and plant 420 Kains Avenue, Albany, via Berkeley. This is a 
small plant manufacturing porcelain bath-room fixtures by the cast- 
ing process from a mixture of California clays. One square up-draft 
kiln is used for both biscuit and glost firing. Four men are employed. 

Tesla: The coal and clay deposits of Eocene (Tejon) age in Corral 
Hollow, near Telsa, and extending for a short distance eastward into 
San Joaquin County, have been known since 1862. These deposits 
have been worked at various times in the past, notably during the 
])eriod from 1897 to 1907. The coal was inferior in quality, and was 
costly to extract on account of steep dij) and swelling ground. As late as 
1919 an attempt was made to reopen the coal mine, at which time the 
property was purchased by the Beckman-Linden Engineering Corpora- 
tion of San Francisco, and considerable sums of money were expended 
on equipment and development before it was clearly demonstrated that 
commercial success could not be expected under prevailing conditions. 
The principal activities in the past have centered around the Tesla 



CLAY RESOURCES AND CERAMIC INDUSTRY 



43 















M'ttii^ 


\ 




f 


1 










I i 


\ 










s 


* \ _ 


'xV 




© 


® } 


® ' 








® 








9 




///" 










/a 










^ 


t 


i 


ill 












1 




] 














% 


1 


]f\ 


p 


■s.^ /-"' 














^ 


s. 1 


n ^ 






\ 














2^ 4 








\ 












•n 


!■? / 


I 






\ 

\ 




© 






® 1 


S 3 // 


In 




® 


""-- 










R 


! /^ 


ill 


















IL 


. 












II 


^fi 


ii 












J 


f //' 1 


1 












.'-..,;/ 


\h 












/'" If 


Mh 










'J7 ^-"-"'X^ ><fHf VOC MV^ 






® 




2^ // is / ///// 




© 








tt'/ if / ///// 












m llllll 












#s' 


m 
















® 7^5 


I 














1 /¥ 








y 








■^ / \i f\i J ///// 

' ® / w/# 




/ 










8 / HfW^^ 


^^'' 




© 








^ / ^kii f 


\ 














xl IN 3 J 


\ 
\ 
^1 

















\ 






— " 




1/© ml 


\ 
\ 








f 


5/ 


4^fWJ ^^ 




,-"'' 


~ 




1 / " 


Mv '■ 








»/ / 


jijiftg^ /--Av 


"i 










i 


*/ J 


4^3/ » 1 


Hj 










n^ 


lx:^^''"m ' ^\\ " 


^ 










^ 


^ // // '■ / 


^ 




/ 






. 


w #-4 


f 


/ 








/ 


/ \r \. W IJ 


T\© 






c 


\ 


J III 


/ 


1 


X 


"^ 


J 







o 

o 
O 



Hi 
ki 
o 

r^ 
S-i 

^6 

bo 

C 

0) 
0) 

c 

"So 

c 
H 

c 

0) 
'O 

c 

3 

-c 

c 

c 

g 

o 



o 
U 

S 



o 
'u 

CO 

■5 



0] 



rt 
S 



44 



DIVISION OF MINES AND MINING 



^ 
§ 






,..:.-...v.-^ a 

( 



\, 



::.^^A 



:•■:% (V. 







8 



03 



i5^' 













I 






>S 









,en^ 



^ 



'^ffMu^ 



crf/si" 









a 
o 

o 

U) 

c 

o 

o 

c 
■5 

H 

c 

0) 

-a 

c 



ft 






'5 



SI 

(U 

E^ 
a 

s 

3 

o 
u 

a 
o 



bo 
o 

o 
<u 

O 






CLAY RESOURCES AND CERAMIC INDUSTRY 45 

miue, in the SE^ of Sec. 26, T. 3 S., R. 3 E., M. D. M., which followed 
wliat is knoAvn as the Eui-eka coal seam 1o a deptli of 800 feet. Some 
work was also done on the Summit seam. See Plate IV for a surface 
map of the district, and Plate V for a {geologic cross-section. In develop- 
ing the coal deposits, extensive beds of clay were found. The clays 
were of various grades, ranging from liigli-gi-ade i)lastic fireclay to 
red-burning sewer pipe and paving-brick clays and shales. Consid- 
erable quantities of high-grade ({uartz sand were also discovered. Two 
clay-working plants were established in llie district, using chiys that 
were obtained from the coal mine, and from tunnels and open-cuts 
nearby. The Carnegie Brick and Potterv Companv produced sewer 
pipe in an 8-kiln plant in the Si of Sec. 30, T. 3 S., II. 4 E., M. I). M., 
two miles east of Tesla, and also had a 45-kiln plant for producing 
fire brick, face brick, and terra cotta at Carnegie, four miles east of 
Tesla. These operations were discontinued in 1912, some years after 
the cessation of coal mining operation.s, as it was not possible to obtain 
an adeqnate supi)ly of suitable cla^'S from the workings near the surface 
after the coal mine was abandoned. 

Tlie district must still be considered as an important potential 
source of high-grade fireclays, as there seems little doubt that extensive 
prospecting would demonstrate the presence of many millions of tons of 
fireclay that would be equal, if not better, in quality to any refractory 
clays now being mined in California. There is little justification at 
I)resent, however, for attempting to rejuvenate clay mining in the dis- 
trict, as the fireclay deposits at lone, Amador County, and at Lincoln, 
Placer County, are adequate in quality and quantity for present needs, 
and are chea])ly mined, mainly from surface workings, whereas under- 
ground mining under difficult conditions would be necessary if extensive 
operations were to be carried on at Tesla. 

Ryan Ranch Deposit: Owned by Wm. Ryan, Livermore. In 1926 
and 1927 a small open pit (see photo No. 2) was excavated on an out- 
crop of fireclay alongside the Livermore-Tesla road in the NW| of Sec. 
26, T. 3 S., R. 3 E., M. D. ]\I. The workings exposed a bed of white 
plastic clay 6 to 8 feet thick, underlain by white sandstone, and over- 
lain by lignitic shale. The strike of the beds is nearly east-west, and 
the dip is about 65° north. Sample No. 259 was taken, and the test 
results on page 263 show it to be an exceptionally good grade of fireclay, 
that burns nearly white. The deposit is apparently a small remnant 
of Eocene enclosed in Miocene rocks, and there is little evidence of the 
continuity of the Eocene at this point. 

Walrich Pottery. J. A. Wall, owner, 1285 Hearst Avenue, Berkeley. 
Art ware, porcelain specialties, decorative and mantel tile are made at 
this plant from a white semi-porcelain body, composed of Illinois silica, 
California (Campo) feldspar, English china and English ball clay. 
Translucent glazes are used, in a wide range of colors. 

]\Iost of the shapes are east, although a few are hand pressed. A 
Callfins kiln, 20 in. by 36 in. by 20 in., heated with oil, is used for firing 
the w^are. The biscuit ware is fired at cone 4, and the glost firing is at 
cone 1. 

Westinghouse Electric and Manufacturing Company. J. W. Ryan, 
manager ; G. ]\[. Whisler, assistant manager ; 6121 Green Street, Emery- 



46 



DIVISION OF MINES AND MINING 



ville. Til is is a branch factory of tlie parent organization of Pennsyl- 
vania. 11 is devoted exclusively to the manufacture of hio-li-voltage 
porcelain iiisulatoi-s and is the ouly ])lant of its kind in California. 
The raw materials used are Campo (California) feldspar, Ottawa (lUi- 




Photo No. 2. Ryan Ranch clay deposit, near Te.sla, 
Alameda County. (Sample No. 259.) 

nois) flint, Kentucky ball clay, Georgia china clay, lone and Lincoln 
(California) sagger clays. 

The feldspar and flint are ground in a ball mill for two hours after 
which thev are mixed Avith the blunged clays. Prom the blunger the 
slip flows 'successively through an agitator, 200 mesh screens, magnetic 
separator, agitator and then is pumped into a filter press where the 



CLAY RESOUHl ES ANT) CERAMIC IXDrSTKV 



47 




s 

3 
O 

U 
S 



u 

a 



o 
U 

do 



u 

0-1 

3 
C 



y 

to 

3 

o 



in 



o 
o 

a 

m 



o 

o 



48 



DIVISION- OF MINES AND MININO 



r 




O 

U 



0) 

£ 

H 

o 
O 

bo 









m 

o 
"5) 



C 
m 



o 



o 

o 

£- 
O 

X 



CLAY RESOURCES AXD CERAIilir INDUSTRY 49 

excess Avater is removed. The filter press cakes are pugj^ed and then 
stored in concrete cellars for about three weeks. The filter press room 
is shown on ]>lioto Xo. '■^. 

Before usin<r, tlie clay is ajrain pujryed to the best size for the insu- 
lator beinj? made. The pup:s of clay are cut to correct length and 
.shaped roiijrhly by hand prior to placing- in the pla.ster of paris mold 
which jiives it the outer shape. Tlie inside shape is made by the modern 
hot press method. A portion of tlie hot press room is shown on piioto 
No. 4. 

From the hot press, the mold and insulator go through a continuous- 
mold release di-yer after which the insulator is easily removed from the 
mold. The next operation is trimming the surface next to the mold 
to include tie wire grooves, and improve the surface condition of the 
in.sulator. 

Trimming is followed by the final drying in a tunnel-type humidity 
dryer wliich operates on a 60-hour scliedule. After drying, an Albany 
slip glaze is applied and the insulators are ready for" firing. Special 
colors can also be supplied for indicating phase, voltage, etc. These 
are white, blue, green, chocolate, black, etc. 

For firing tiie insulators are placed in saggers which in turn are 
placed in one of four draft kilns. Each kiln is 16 feet in diameter and 
12 feet high to the crown and the average burn is 800,000 cubic inches of 
ware. The firing is done with gas for the first few hours after which 
oil is u.sed for the 60 hr. period. The temperature is controlled bv 
means of recording pyrometers and pyrometric cones. The finishing 
temperature is cone 10 down (approximately 1260 degrees C). The 
cooling period is about three days. 

An average of sixty-five men are employed in this plant. 

Woolenius Tiles. C. A. Elsenius, OAvner and manager, 1631 Woolsey 
Street, Berkeley. This is a small plant engaged in the manufacture of 
decorative tile, inserts, and mantel pieces, using a fireclav bodv made 
from Lincoln clay (sample Xo. 146, p. 303) and Shepard^ (Tone) sand 
(sample Xo. 128, p. 261). The clays are pulverized to 50-mesh, 
pugged, and regular shapes are made in a tile auger. Special designs 
are hand pre.s.sed. A thin matt glaze is fired on with the body, ancl is 
afterwards partly ivmoved by buffing on a wheel. A rectangular 
down-draft kiln, heated with oil, is used for firing. The finishino- 
temperature is from cone 5 to cone 7. " 

One or tAvo men are employed besides the owner. 

liibl (Clay Resources of Alameda Countv) : State Mineraloc'ist's 
Repts X, IX 91 ; XTI, p. 39 ; Xin, p. 5] ;" XIV, p. 607. Cal. State 
Min. Bur. Bulletin Xo. 38, pp. 202, 204-206, and 227 • Prel Rept 
Xo. 7, i)p. 35-37, 94. U. S. G. S. 22d Ann. Rei)t., Pt III pp 
501-504. ' ' ^^ 

AMADOR COUNTY. 
General Features. 

Amador County lies to the east of the Sacramento Valley and extends 
from the lower foothills to the summit of the Sierra Nevada It 
traverses the center of the famous I\Iother Lode gold belt, and is similar 
to El Dorado, Calaveras, Tuolumne and Mariposa counties in climate 
physiography, geology and natural resources. Amador is the smallest 

4 — 54979 



50 DIVISION OF MINES AND MINING 

county of the group, and contains 6U1 .s(j[uai-e miles. Tiie population 
is about SOOO. Ciold and clay mining and stock raising are the prin- 
cipal industries. Tlie county is well ])rovided with good roads, con- 
necting the princii)al towns with each other, and with the Sacramento 
Valley. A branch of the Southern Pacific Railroad extends from Gait 
to lone, where it connects with tlie Amador Central, running to Martel 
and serving the gold mines in the vicinity of Jackson and Sutter Creek, 
the principal towns in the county. There is timber suitable for under- 
ground mining in the mountains. Electric power is supplied to most 
of the towns in the county by the Pacific Gas and Electric Compau}-, 
and water is supplied by this company to the Mother Lode section of 
the county. 

The geology and mineral resources of tlie county have recently been 
summarized by Logan •? 

"White clay forms a conspicuous part of tlie lone (Tertiary) beds, which extend 
across the entire west side of the county from north to south. This and other 
colored clays nearby form the basis of an important industry, supplying potteries 
in various parts of the state. 

"Also associated with the lone beds and usually within 100 feet or less of the 
surface, near Carbondale, lone, Buena Vista and Lancha Plana, occur numerous 
deposits of brown lignite. This was mined at several places until a few years ago. . . . 

"Farther east, alternating beds of Mariposa (Jurassic) black slate, amphibolite 
schist, serpentine and Calaveras (Carboniferous) rocks extend northwest, parallel 
to the axis of the mountain range of which they form the Hank. In the amiptibolite 
schist numerous copper mines and prospects occur, but are all idle now. Ohromite 
occurs in the serpentine, and many small lenses of limestone in the Carboniferous 
rocks. These formations begin about a mile east of lone and extend for seven 
miles eastward, where the Mother Lode mines occur, in another belt of black 
Mariposa slate. This slate enters the county at Middle Bar bridge on Mokelumne 
River, running thence northwest tlirough and beyond the county. Vk^ith an average 
width of about one-half mile, and in many of the mine workings narrowing "to only 
a few hundred feet, this slate belt and the immediatel.y adjoining and at times 
intercalated areas of altered igneous rocks contain all the important gold quartz 
mines of the county. 

"To the east of the Mother Lode the rocks are nearly all of Carboniferous age for 
a distance of ten miles, until an elevation of al^out 3000 feet is reached, where the 
granodiorite forming the core of the mountains appears. At Oleta in the northern 
part of the county and at Volcano much placer gold has been produced. A series 
of detached gravel bodies covered by rhyolite and andesite extends across the county 
between these two old camps. The gravel in this region represents remnants of Tertiary 
river deposits. In the western part of the county, near lone, are accumulations of 
delta and shore gravel, deposited when the inland sea or gulf had its shores in that 
vicinity, during the time of the lone disposition, which was at the same time as the 
formation of prevolcanic channels m the rivers of the Sierra Nevada. In places 
where it has been reconcentrated by later streams some of it has been rich enough 
to mine profitably. There are also beds of white and red sandstone in the lone 
formations, which have been worked in the past. Marble occurs two miles east of 
Plymouth and eight miles east of Sutter Creek, enclosed in the Calaveras formation. 
Besides the numerous small bodies of limestone, ther# are two especially large areas, 
one at Volcano and one four miles northwest of that town. Asbestos, talc, ocher 
and low-grade iron ores also occur." 

Clay Resources." 

The lone-Carbondale district is noted for its high-grade fire clays and 
fire sands. Associated with the high-grade clays and sands are a 
number of important red-burning plastic clays. A fire brick plant has 
been in operation near lone for many years. An experimental clay 
washing plant was operated a number of years ago on the N. Clark 
and Sons property near Carbondale (see Plate VI), and another wash- 
ing plant was operated near lone by the Philadelphia Quartz Company. 
Both of these operations were abandoned prior to 1921, but in Febru- 
ary, 1927, a new plant was erected on the Carlile property by E. E. 
Tremain, lessee. 



^ Logan, C. A., Amador County; State Mineralogist's Report XXIII, p. 132, April, 
1927. 

- The report by Logan, op. cit., was freely drawn upon in the preparation of this 
summary. 



rT.4V RVSOTTRPFS AVH PF.RAAfTr TNDT'STRY 



51 



50 DIVISION OF MIXES AND MINING 

county of the group, and contains 601 square miles. The population 
is about 8000. Gold and clay mining and stock raising are the prin- 
cipal industries. The county is well j)rovided with good roads, con- 
necting the principal towns with each other, and with the ISacraniento 
Valley. A branch of the Southern Pacific Railroad extends from Gait 
to lone, where it connects with tlie Amador Central, running to Martel 
and serving the gold mines in the vicinity of Jackson and Sutter Creek, 
the principal towns in the county. There is timber suitable for under- 
ground mining in the mountains. Electric power is supplied to most 
of the towns in the county by the Pacific Gas and Electric Company, 
and water is supplied by this company to the Mother Lode section of 
the county. 

The geology and mineral resources of the county have recently been 
summarized by Logan :^ 

"White clay forms a conspicuous part of the lone (Tertiary) beds, which extend 
across tlie entire west side of the county from nortli lo south. This and other 
colored clays nearby form the basis of an important industry, supplying potteries 
in various parts of the state. 

"Also associated with the lone beds and usually within 100 feet or less of the 
surface, near Carbondale, lone, Buena "Vista and Lancha Plana, occur numerous 
deposits of brown lignite. This was mined at several places until a few years ago. . . . 

"Farther east, alternating beds of Mariposa (Jurassic) black slate, amphibolite 
schist, serpentine and Calaveras (Carboniferous) rocks extend northwest, parallel 
to the axis of the mountain range of which they form the flank. In the amiphbolite 
schist numerous copper mines and prospects occur, but are all idle now. Chromite 
occurs in the serpentine, and many small lenses of limestone in the Carboniferous 
rocks. These formations begin about a mile east of lone and extend for seven 
miles eastward, where the Mother Lode mines occur, in another belt of black 
Mariposa slate. This slate enters the county at Middle Bar bridge on Mokelumne 
River, running thence northwest through and beyond the county. W'ith an average 
width of about one-half mile, and in many of the mine workings narrowing -to only 
a few hundred feet, this slate belt and the immediately adjoining and at times 
intercalated areas of altered igneous rocks contain all the important gold quartz 
mines of the county. 

"To the east of the Mother Lode the rocks are nearly all of Carboniferous age for 
a distance of ten miles, until an elevation of about 3000 feet is reached, w-here the 
granodiorite forming the core of the mountains appears. At Oleta in the northern 
part of the county and at Volcano much placer gold has been produced. A series 
of detached gravel bodies covered by rhyolite and andesite extends across the county 
between these two old camps. The gravel in this region represents remnants of Tertiary 
river deposits. In the western part of the county, near lone, are accumulations of 
delta and shore gravel, deposited when the inland sea or gulf had its shores in that 
vicinity, during the time of the lone disposition, which was at the same time as the 
formation of prevolcanic channels m the rivers of the Sierra Nevada. In places 
where it has been reconcentrated by later streams some of it has been rich enough 
to mine profitably. There are also beds of white and red sandstone in the lone 
formations, which have been worked in the past. Marble occurs two miles east of 
Plymouth and eight miles east of Sutter Creek, enclosed in the Calaveras formation. 
Besides the numerous small bodies of limestone, therdT are two especially large areas, 
one at Volcano and one four miles northwest of that town. Asbestos, talc, ocher 
and low-grade iron ores also occur." 

Clay Resources.- 

The lone-Carbondale district is noted for its high-grade fire clays and 
fire sands. Associated with the high-grade clays and sands are a 
number of important red-burning plastic clays. A fire brick plant has 
been in operation near lone for many years. An experimental clay 
washing plant was operated a number of years ago on the N. Clark 
and Sons property near Carbondale (see Plate VI), and another wash- 
ing plant was operated near lone by the Philadelphia Quartz Company. 
Both of these operations w^ere abandoned prior to 1921, but in Febru- 
ary, 1927, a new plant was erected on the Carlile property by E. E. 
Tremain, lessee. 



1 Logan, C. A., Amador County; State Mineralogist's Report XXIII, p. 132, April, 
1927. 

= The report by Logan, op. cit., was freely drawn upon in the preparation of this 
summary. 




MAP 0'=~ 

/ONE D/5TR/CT 

AMADOR COUNTY, JZALJ/T 
S/-/C\V/AiO BOUNDA/RIES 

or 
ARROYO SECO GRANT. 

CLAY DEPOS/rS 



T6N 
|T5N 



Plate VI. PioiJerly map of lone district. (By courtesy ot S. E. Kieffcr. ) 



[14'JT9 — lacing page 50 



50 



DIVISION OF MINES AND MINING 





CLAY RESOURCES AND CERAMIC INDUSTRY 51 

Enougli int'onnatioii lias been obtained from those various wasliing 
operations to doinonstrate the fact that it is possihh' to prodneo a quartz 
sand suitable for tlie inanufaeture of <ilass and sodium silicate, and for 
use as "flint" in porcelain bodies. The kaolin content of the sands 
is seldom in excess of 25^>, and "reuerally contains enough iron oxide to 
cause it to fire to a lifrht-ci-i'am coloi-, althoujih in ])laces it is sufficiently 
pure to tire to a satisfactory white coioi' for use in white-ware bodies. 
Several factors adversely affect the establishment of a financially-sound 
washing operation in the district, among which may be mentioned the 
c()m])aratively high freight rate to i)roducing centers, the low cost of 
IJelgiau saiul, which is delivered to California jjorts at a price of 
about $5 per ton, the low content of high-grade kaolin in most of the 
sands, and the fact that few important plants now using English or 
Florida kaolin would be willing to change to the use of local material 
unless as.sured of aji ample supply of uniformly high-grade kaolin over 
a long period of years. 

A new use for lone sand is in making white cement. One large 
company has recently bought a sand property, and it is anticipated that 
others will follow. 

The clays occur as a part of the lone formation and are distributed 
over a length of 12 miles and a wadth of 4^ miles in the county, with 
extensions into Sacramento County on the northwest and into Cala- 
veras County on the southeast. In most places the clays are covered 
by an overburden of soil, sand, tuff, volcanic breccia, and sandstone, 
varying from a few inches to a maximum of 20 feet over most of the 
depo.sits now being worked. The clay beds have a slight westerly dip. 
Lignite coal, interbedded with clay, is found at depths of 40 to 125 feet. 
The clay beds are not continuous, and the extreme limits of the i)robable 
boundaries of the deposits have not been determined, but enough mining 
and drill prospecting has been done to demonstrate the fact that there 
is an ample supply of clay for many years. 

The contemporary theory of the origin of the clays has been well 
summarized by Logan. ^ 

"The white clay apparently came from the rhyolite ash flow.s, which have been 
found directly over the older series of gold-bearing gravel channel.s in the Sierra 
Nevada. Probably a long enough i)eriod of erosion ensued after these initial ash 
outljursts to ])ermit the carrying of the finer sized and lighter particles down the 
streams into the shore waters of the inland sea which then filled the Sacramento and 
San .Toaquin vallejs. P.efore the white ash was covered and jircserved by later flows 
of darker colored lireccia and ash, a large i)art of it was thus swept away. 

"That the clay is of rhyolitic origin, possibly mixed with the quartz sand from 
those mysterious earlier rivers whose remaining sections now show such a remarkalile 
amount of quartz cobbles, with scarcely any other rock, is substantiated by the 
analyses. The sandy clay carries about 70% silica, 20% alumina. 1.25% iron oxides, 
0.3% CaO, and 0.2% MgO. Other samples where the p<»rcentage of silica is less, 
contain 32% to 34% dry weight of alumina. The amount of calcium is typically 
low and it is erratically distributed, sometime.s as gypsum seams. As the percentage 
of iron increases the clay becomes mottled red and yellow, but the usual color is 
white, cream or light lilue." 

Arroyo Seco Grant. 

Introduction. 

The greater part of the lone clay deposits lie within the boundaries 
of the Rancho Arroyo Seco, which was formerly owned by the McKis- 
sick Cattle Company, who leased many of the clay deposits to Bacon 
& Bacon (see post) and other operators in the district. In 1926 the 
grant was purchased by S. E. Kieffer, 57 Post Street, San Francisco, 

' Op. cit., p. 135. 



52 



DIVISION OF MINES AND MINING 



who then leased the clay j^roperties to G. A. Starkweather. ]\Ir. Stark- 
weather is operating some of the properties, but has subleased a num- 
ber of them to various ojierators. A map of tlie prant, and of the 
surrounding pro])erty, sliowiufj- the location of tlie i)rincipal clay 
deposits, is sliown on plate VI. 

Core Drilling. 

Durin<r the seasons of 192o and 1926, a larpre amount of core drilling 
Avas done in the lone district under the direction of ]\Ir. S. E. KiefFer, 
consulting engineer. Many of these holes penetrated the sand, clay and 
coal beds to depths of 150 feet or more. Through the courtesy of ^Ir. 
KiefPer, a number of core-drill clay samples were obtained for testing. 
The location of the holes from which these samples were taken is 
shown on the map, plate VI, and the approximate depth of the samples 
from the surface, as well as the approximate thickness of each forma- 
tion, are given in table No. 8. 









TABLE NO. 8. 






Descr 


ption of Core Drill Samples from 


lone District. 








Depth 










of top 


• 








of .sample 




Sample 


Drill 


Location 


from Thickness 


General 


No. 


hole No. 


of hole 


surface, of forma- 


character of 


239 




XE. cor 


feet tion. feet 


material 






Lot 254 


37 25 


Fire sand 


240 




E. side 










Lot 237 


100(?) 


Plastic firclay 


243 


47 


Lot 336 


230 16 


Sandy clay, poor quality 


244 


54 


Lot 324 


13 19 


Plastic fireclay 


245 


55- 1 


Lot 237 


32 41 


Plastic fireclay 


247 


55- 2 


Lot 237 


73 18 


Plastic fireclay 


246 


55- 3 


Lot 237 


93 16 


Plastic fireclay 


248 


56- 1 


Lot 237 


4 24 


Plastic fireclay 


249 


56- 2 


Lot 237 


44 36 


Plastic fireclay 


250 


56- 3 


Lot 237 


80 30 


Plastic fireclay 


251 


57- 1 


Lot 237 


3 9 


Plastic red-burning 


252 


57- 2 


Lot 237 


12 10 


Plastic fireclay 


253 


57- 3 


Lot 237 


22 20 


PL fireclay, nearly white 


254 


57- 4 


Lot 237 


42 26 


Buff plastic fireclay 


255 


57- 5 


Lot 237 


68 46 


Red plastic, cone 26 


256 


60 


Lot 255 


(near — 
hottom) 


Red plastic, cone 19-20 


257 


62 


Lot 255 


66 6 


PI. fireclay, nearly white 


258 


61 


Lot 255 


75(?) 10(?) 


Buff plastic fireclay 



It is not po.ssible from the data available to establish continuity of 
the various beds of clay and sand represented by the core drill samples, 
but the presence of large reserves of high-grade clays is well demon- 
strated, Mo.st of these clays, however, can not be mined under present 
conditions while large deposits of good material are still available for 
open-pit mining. 

Active Deposits. 

Gage Pit. The Gage pit, leased and operated by G. A. Starkweather, 
is in Lot 224 of the Arroyo Seco grant, two miles east of Lignite siding 
on the Southern Pacific Railroad northeast of lone. The clay is 
dazzling white in color, slightly plastic, and has a talcy feel. It has 
been used by the West Coast Calcimine Co. The pit at the time of 
visit, in August, 1925, was 100 feet wide at the face, which had 
advanced 120 feet from the approach. The exposed clay bank was 12 
feet thick. ^Mr. Bacon stated that the total average thickness of this 



CLAY RESOURCES AND CERAMIC INDUSTRY 53 

clay is 16 feet. The clay is capped by less than three feet of volcanic 
breccia. 

A view of tills pit, looking? eastward, is shown on pholo No. '). 
ISample Xo. 120 was taken for test, the results of which are given on 
page 273. Tlic usiuil annual i)roduction is 600 tons, all iiiined and 
loaded by hand and hauled in auto trucks to Lignite. 

Jones Butte Deposit. The Jones Butte clay mine, sub-leased from 
Mr. Starkweather and operated by the Stockton Fire Brick Co., is in 
Lot 240 of the Arroyo Seco grant, on the western slope of Jones Butte, 
also known to local iniuibitants as Deutschke Hill. The mine is 1.5 
miles by road fi-om Edgar siding, on the Southern Pacific Railroad, 
two miles northwest from lone. 

A geological study of the deposit was made by C. X. Scluiette, at 
one time in the employ of the Stockton com])any as a geologist and 




Photo No. 5. Gage clay pit, near Lignite, looking eastward. (Sample No. 125.) 

engineer. The successive formations, from the top of the hill down- 
ward, are lava, tuff, gravel, clay, and lateritic iron. The clay bed is lens 
shaped in the north-south section of the hill, and wedge shaped in the 
east-west section, thinning toward the east. The cldy in the mining 
area covered by o])erations in August, 1925, was 8 to 10 feet thick and 
there was an additional 2-foot bed of extremely 'fat' or 'unctuous' clay 
in the roof. The floor has a general pitch toward the south, and min- 
ing is complicated by the presence of .sharp rolls in the floor in places. 
The floor is generally red lateritic iron, but in idaces this is covered 
by a variable thickness of yellow plastic clay. 

The mine is worked entirely by underground methods. The general 
plan, modified by local irregularities, is to run drifts in a general 
easterly direction on a slightly ascending grade on approximately 
20-foot centers. The drifts are as .small as is consistent with efficient 
driving and tramming, usually five by seven feet. Upon reaching the 
limit of the block to be mined, or the limit of workable thickness, the 
retreat is made by slabbing to the roof and slicing a five cut from each 



54 



DIVISION OF MINES AND MINING 



side of the drift, leaving a pillar approximately 5 feet in width to sup- 
port the rooms while the retreat is in progress. The minimum extrac- 
tion of clay in the minable area is thus 75% of the total. Where the 
roof is strong enough, the extraction can be increased by further pillar 
robbing. 

At the working faces, mine cars are loaded by hand shoveling, and 
are trammed by hand for a minimum distance of 400 feet to a bin near 
the portal of the tunnel. From here the clay is drawn off into an auto 
truck for transportation to the car-loading bin at Edgar. 

The mine is normally operated on a production schedule of four cars 
(total 200 tons) per week for a period of four months, or somewhat 
in excess of 3000 tons of clay per year. The number of men employed, 
including a foreman and a truck driver, is five. 

Three samples were taken. No. 120 is the main 'Edwin' clay. The 
test results, page 272, indicate that it is one of the best pla.stic fire- 




Photo No. G. Jones Butte Mine. Arroyo Seco Raiicho, facing eastward toward 
portal of tunnel. (Samples No. 120, 121 and 122.) 



clays in California, but shows the high shrinkage and fire cracking 
typical of the lone clays. Sample No. 121 is the ' unctuous ' clay occur- 
ring in the roof of the mine. It was taken, and the test work done (see 
page 302), as a matter of general interest, altliough the known thick- 
ness of the bed is insufficient for commercial i)roduetioii. Sample No. 
122 is the ' Laterite, ' which has no present commercial value, but is con- 
sidered of sufficient interest to warrant a record of its properties, which 
is given on ]iage 328. 

A view of the propciiy near the jiortal of tlie tunnel is sliown on 
photo No. (j. 

Shepard Pit (lea.sed by G. A. Starkweather). The Shepard sand 
pit is f mile from lone at Shepard spur on the Amador Central Rail- 



CLAY RESOURCES AND CERAMIC INDUSTRY 



55 



i-oad. The easteru boundary of the property adjoins the Avostern 
boundary of the Newman sand pit. A vieAV of tlie pit is shown on photo 
No. 8, from Avhich the extent of open pit mining and the present method 
of underground mining by pillar and room can be seen. The sand 
has an avn-aut' tliickupss of Ki feci. The capping of volcanic breccia 




Photo No. 7. Barber ur Sliei)ard .sand pit one mile east of lone. 




Photo No. 8. Sand pit subleased by U\o lone Fire Brick Co. (Sample No. 140.) 

is sufficiently strong so that rooms can be driven into the deposit 
nearly to the full height of the sand bed, and wide enough to permit 
the entrance of auto trucks to the loading face. Round pillars of sand 
are left at api)roximately 25 foot intersections, to support the back. 
The sand has been mined in this fashion over a considerable area. See 
])hoto No. 7. 



56 



DIVISION OF MINES AND MINING 



Sample No. 128 was taken for test, the results of which are given on 
])aij'e 261. The sand is fine grained, nearly wliite, and contains enougli 
clay to develop slight i)lasticity and bonding power. It is widely 
used by fire brick and terra cotta manufacturers as a fine grog. The 
normal output from the Shepard pit is 15,000 tons per year. At the 
present rate of mining, the reserve of sand in sight is sufficient for manj' 
years, although mining costs will be higher as mining proceeds fartlier 
from the openings into the rooms. 

Photo No. 8 shows a nearby sand pit, subleased by the I one Fire 
Brick Co., from which sample No. 140 was taken. See page 280. 

Yam Deposit. The Yarn clay pit, leased and operated by G. A. 
Starkweather, is located on lot 232 of the Arroyo Seco grant, 100 yards 
north of a siding at Lignite on the Southern Pacific Railroad, four 
miles northwest of lone. 

Photo No. 9 is a view of this ]nt. The overburden is less than three 




Photo No. 9. Yaru clay pit, lone. (Samples No. 123, 124.) 

feet in thickness. The upper bed (sample No. 123, p. 335), clearly shown 
in the photograph, is designated Yaru No. 2. It is a yellowish and 
blue-gray plastic fire clay 6 feet thick. The lower bed (sample No. 
124, p. 302), is known as Yaru No. 1, and is somewhat lighter in color, 
but contains yellowi.sh streaks along fracture planes, and occasional 
nodules of iron-stained sand. A car hoist is used to elevate the clay 
from the bottom of the pit to a hot)per on the surface where it is dumped 
into a truck for the short haul to the railroad siding. The thickness 
of Yaru No. 1 exposed by mining operations is 25 to 30 feet. Borings 
in this clay are said to indicate a total thickness of 90 feet, but 
streaks of sand are encountered in places. 

Total shipments of Yaru No. 1 and No. 2 are normally 4000 tons per 
year. 

Miscellaneous Operations. 

Bacon cf' Bacon. Mark J. Bacon, manager, lone. This firm is 
engaged in a general clay-mining business, working some properties for 



CLAY RESOURCES AND (■KRA:\Iir INDITSTRY 57 

the owin'1-s under contract and also sliipping to numerous consumers 
from pits which they own oi- K-ase. Twenty-five men, two steam 
shovels and six ti-ucks arc employed during the operating season from 
early in A{)ril to the end of the dry season. 

Two of the properties owned by Bacon and Bacon are here described, 
the Bacon Ked (Lane mottled) and the Chocolate i)its. 

Bacon Red: This is on an 80-acre tract, comprising the NW} of 
Sec. 32, T. 6 N., R. 10 E., M. D. M., near the intersection of the Jack- 
son highway and the Amador Central Railroad, 1.8 miles southeast of 
lone. The clay is a fine-grained plastic, red-wliite mottled clay (sample 
No. 127, ]). 335). and is quite characteristic of the region. It is mined 
from an oi)en ])it, 150 feet long at the face. In 1925 the pit had 
advanced 60 feet in from the starting ])oint, and the exposed clay baidv 
was 15 feet high, covered by shallow overl)urden of loose gravel. The 
overburden will gradually increase as the clay is followed into the 
hill, but the maximum thickness of overburden will probably not be 
excessive, as the hill is low, and has a gentle slope. The clay is evi- 
dently not bottomed by the floor of the i)it, and it is stated that the 
total thickness of clay, as determined by boring, is nearly 40 feet. 

The normal production from this pit is 1000 tons per year, all mined 
by hand. There is no siding at the ])it, the clay being hauled in trucks 
to one of the loading platforms maintained by Mv. Bacon. 

Chocolate Pit : The chocolate pit is 3 miles north of Carbondale. 
Two varieties of clay are mined from this pit. The upper bed, 4 to 5 
feet thick, is a chocolate-colored plastic clay (sample No. 137, p. 266) 
of special value in the manufacture of saggers. This is underlain by 
Ihe Bacon bottom (sample No. l-'}8, p. 280), a 4—5 foot bed of white- 
burning i)lastic clay occasionally used in sanitary ware bodies. The 
overburden is less than four feet thick, so that these clays can readily 
be quarried. 

The ])roduction from this ])it has been small, mainly on account of 
the length of haul compared to other varieties that have nearly the 
same properties. About 500 tons of chocolate and 100 tons of Bacon 
bottom are mined each year. The ]iit was 150 ft. long, and 40 ft. 
wide at the time of the visit in July, 1925. 

CarJile Claij and Sand Dcpusit.^ Mrs. Sarah E. Carlile, lone, owner; 
E. E. Tremain, Buena Vista, via R. F. D., lone, lessee. The propertv 
contains 60 acres on W| NW] Sec. 8, T. 5 N., R. 10 E., M. D. M., four 
miles from lone and 2.8 miles bj^ road to the nearest railroad spur. 
The property was not worked prior to 1927. 

In February, 1927, a plant was being erected to wash the sand and 
clay. A bed of wdiite sandy clay, overlain by two to seven feet of 
brown clay, had been stripped over an area about 80 feet square. 
According to present i)lans, the clay will be dug by drag-line sci-aper. 
The washing and settling plant comprises several hundred feet of 
sluices with sand traps and eight large clay-settling tanks. The sand is 
expected to settle out on the way through the sluices and traps, leaving 
the clay in suspension, free from grit, to pass to the settling tanks, 
from which it will be drawn, after which it will be filtered and dried. 

'Entire description by C A. Logan, op. cit.. ji. 130, who visiterl the i)roi)erl\- in 
1927, after construction work had been started. 



58 DIVISION OF MINES AND MINING 

The estimated capacity is 10 tons a day. The sand is not at i)resent 
being considered for marlvcting. 

The author visited the property in 1926 before construction work had 
been started, and took a sample. No. 208, from a shallow open pit. The 
test results are on page 262. 

N. Clark and Sons (see under Alameda County) own two important 
pits in the lone district, tlie Clark sand pit and the Doscli clay pit. 

Clark Sand Pit : The Clark sand pit, owned by N. Clark and Sons 
of San Francisco and Alameda, is an HO-acre property in the SW| 
of Sec. 28, T. 7 N., R. 9 E., 1.8 miles by road northeast of Carbondale. 
and 0.8 miles northeast of the Harvey claj' pit. The sand bed is 25 
to 40 feet thick, and is overlain by a variable thickness of volcanic 
breccia. Most of the sand not requiring stripping has been removed 
by open pit methods, the pit covering more than an acre. Present 
mining is by the room and pillar method, similar to that used at the 
Shepard and Newman pits. The extent of the workings, size of rooms 
and ])illars, and general plan is nearly the same as in the Shepard pit. 

Some years ago an experimental washing plant was built near this 
])it, to study the economic possibilities of washing the sand to produce 
a high-grade clay and a white sand as separate products. The experi- 
ments were abandoned for various reasons, among them the lack of 
sufficient water, and the lack of profitable market for the sand. 

Sample No. 134 was taken for testing, the results of which are given 
on page 261. These should be compared with the results on samples 
No. 128, 129, and 140. 

The normal production of Clark sand is 5000 to 7000 tons. It is 
loaded by hand into trucks and hauled to Carbondale. 

Doscn Pit : The Dosch clay pit is in Lot 222 of the Arroyo Seco 
grant, near the lone-Sacramento highway at a point three miles north- 
west of lone, and one mile from Clarksona siding on the Amador branch 
of the Southern Pacific Railroad. The Dosch clay is the best known of 
the lone clays, and production from this pit is considerably greater than 
from any otlier plastic clay deposit in the district. 

Two varieties of clay are diiferentiated. The Dosch stripping, sample 
No. 135 (see p. 312), includes the upper beds that are more or less 
contaminated by surface infiltration of water carrying iron salts. The 
thickness varies, but is usually less than 10 feet. This clay is useful as 
an ingredient of sewer-pipe mixes. The Dosch clay, sample No. 136 (see 
]). 302), underlies this to a maximum thickness of 80 feet. It is a 
])lastic fireclay, used for terra cotta, ])ottery, and stoneware. At the 
time of visit in 1925 and 1926, the pit was about an acre in extent, and 
the height of the face was 40 feet. Mining is by steam shovel, loading 
into 5-ton trucks. Four trucks are in service to haul the clay from the 
pit to Clarksona, where it is stored in a large covered warehouse, and 
loaded into railroad cars as needed for shipment. A supply of clay 
is thus available during the winter months, Avhen mining is stopped. 

The production is 4000 tons of Dosch stripping and 10,000 to 12,000 
tons of the underlying Dosch clay }ier year. 

W. S. Dickey Clay Mannfacturinu Company. The Fancher pit, 
under lea.se to the AV. S. Dickey coiu])any, is on the northerly sloi)e 
of Jackson Vallev, one mile west of Buena Vista, 3.75 miles air 



CLAY RESOURCES AND CERAMIC INDUSTRY 



59 



line S. 3° E. from lone, or 5.1> riiiles by road south of Wallon siding, 
on the Amador Central Railroad. 

Photo No. 10-A is a view of this pit, taken on August 8, 1925. The 
strip])iiig of loose sandy and gravelly soil attains a maximum thickness 
of 2U feet in the present pit, but will gradually increase as mining 
operations advance northward. Two varieties of clay are differentiated. 
The upper bed (sample No. 141), six to ten feet thick, is a yellowish 
fireclay, containing occasional iron stained boulders. This is underlain 
by at least 15 feet of hard blue-gray plastic clay (sample No. 142), 
which at the time of visit was not in use. The results of tests on these 
varieties are given on i)age 280. 

The method of mining ])revious to 1927 is clearly illustrated in the 
pliotograph. Hand picking and light blasting was used to loosen tlie 
clay from tlie bank, wliere it was picked up by a tractor-drawn scraper, 
dragged up an incline, and dumped into a hopper over the tunnel, 




Photo No. 10-A. Fancher clay pit, Jackson Valley, near lone, leased by W. S. 
Dickey Clay Mfg. Co., facing northwest. (In 1925.) (Samples No. 141 
and 142.) 



from which it was delivered to an auto truck. A one-ton Ford truck is 
used for hauling the clay to Wallon siding. Beginning in 1927, the 
thickness of overburden has been such that the mining method was 
changed to tunneling. 

Eckland Property. Mrs. C. Eckland, 1743 N. Hunter Street, Stock- 
ton, owner. This property consists of 80 acres, lying to the south of 
the lone-Jackson highway at the point where it crosses the railroad, 
1.5 miles ea.st of lone. The property is at present (1927) idle, but 
was at one time worked by Mr. Dennison of lone. Yellow, i)ink, 
and red-mottled plastic clays are exposed in the walls of the abandoned 
pit, from which sample No. 213 was taken (see page 299). \Vm. Haver- 
stick of lone supplied a .sample (No. 209, p. 263) of white sandy clay 
from a 16-foot drill hole on the southwestern portion of the property. 
Almost the entire property is covered with an overburden of volcanic 



60 



DIVISION OF MINES AND MINING 



breccia, and insufficient i)ros|)ecting has been done to determine tlie 
extent and character of the underlying clay beds. 

lone Fire Brick Co., J. T. Roberts, president and general manager, 
12 Russ Building, San Francisco ; Wm. Brown, superintendent at 
lone. The lone Fire Brick Co., a subsidiary of the Stockton Fire Brick 
Company, is located about two miles southeast of the town of lone, 
on a spur track of the Amador Central Railroad. JNIachine-made fire 
brick are made, using a mixture of Lincoln clay, now secured from 
the pit of the Clay Corporation of California at Lincoln (sample No. 
280, p. 305), and lone clay, sand (sam])le No. 140, p. 280), and grog 
from pits near the plant. 




Photo No. 10-B. Brick machinery in plant of lone Fire Brick Company. 
(Photo by courtesy of the company.) 

The mixture is prepared in a dry pan and pug mill, shaped in an 
auger machine, wire cut (side), and repressed. Drying is accomplished 
in air under sheds and in the open. Only such standard shapes as 
can be made on the auger machine are manufactured at this plant, there 
being no hand molding. Photo No. 10-B is an interior view of the plant, 
showing an auger machine and two re])resses, with off-beai'ing con- 
veyors. 

The firing equipment consists of five oil-fired round down-draft 
kilns, having a total capacity of 11,000 brick per day. The auger 
machine capacity is 20,000 brick ])er day, which makes it possible to 
prepare a sur])lus for storage to be fired during the winter months, 
when clay mining can not be economically carried on. 



CLAY RESOURCES AND CERAMIC INDUSTRY 61 

Groc: Groo; for use in llic phiiil of llic lone Fife liriek Company is 
mined fi"om a small i)i1 adjoining- the Uacon I'ed day i)i1. A six to 
twelve foot bank is exposed, over a len«rtli of 100 fi'et. 'Phe material 
consists maiidy of i)artly-rounded (piarl/ <>ravel, most of Aviiieh is 
under two inches in diameter. The interstices are partly filled with 
fine sand, with a small amount of clay, li'on stainin«>' is a ])rominent 
macroscopic feature, but the total iron content is not too high to permit 
the production of .second-j>rade fire brick when used as the sole grog 
constituent. 

Sand: The sand ])it of the lone Fire Brick Com])any is lu'ar the 
grog pit and is shown on photo No. 10-C. 

May E. Xewnum Estate. "Slain otYice, 980 lUish Street, San Fran- 
cisco. The pit is on a 150-acre proi)erty in Sees. 20, 80, and .'U, T. 6 
N., I\. 10 E., M. D. M., on the Amador Central Railroad, one mile south- 
west from lone, and less than a half mile northeast from the plant of the 
lone Fire Brick Co. 

The bulk of the output from this property up to date has been lone 
sand, but plastic red clay beds have been found, and a small amount 
has been shii)])ed. The main sand pit abuts the railroad tracks on its 
eastern boundary. The sand occurs in two separate beds each 10 to 15 
feet thick and separated by a bed of carbonaceous sand from 6 to 30 
feet thick. Volcanic breccia of variable thickness overlies tha deposit. 
Open-pit mining was used at first, but practically all of the sand not 
covered by volcanic breccia has by this time been removed, and ])resent 
mining is by underground methods, using the room and pillar method. 

The general plan of mining, M'henever a systematic lay-out is possible, 
is to drive rooms in the bottom of the upper bed approximately 10 by 
10 feet in cross-section on 25 foot centers to the limit of the block of 
ground being mined, usually about 250 feet, then retreat by excavating 
to the roof, and by cutting across to adjacent rooms, finally reducing the 
j^illars to a])])roximately six feet in diameter. The sand is loaded by 
liand into small cars, which are dumped into a loading chute at the 
entrance of the mine. The loading chute delivers to mine cars which 
are in turn hauled up an incline and out of the pit by a car hoist, 
finally delivering the sand to a loading bin on the railroad siding. 

Some of the lower sand bed has been mined and shipped from 
places where it has been exposed by open-pit mining. The present 
underground method does not leave the mine in a satisfactory condi- 
tion for the recovery of the low^er bed in the future, unless the capping 
of volcaiiie breccia can be utilized as grog, and the bed of carbonaceous 
sand is strip]ied. Seven or eight men are employed during the dry 
months, when an average of 9 cars per week is ship])ed. The annual 
output varies with demand, and is normally in excess of 6000 tons. 

Since the above was written, the property was visited in 1927 by Mr. 
Logan, from whose report' the following additional notes are taken : 

"The old pits, operated for years south of the track, have been worked up to the 
property line. A new i)it has recently been started on the north side of the track. 
In vertical section, so far as opened, it shows from top to bottom 2.5 feet of over- 
burden 10 feet of red mottled clay, and 15 feet of white sand. The red mottled 
clay now being shipped for testing (April 13) is said to carry a little more sand than 
the iAcon mottled clay. Nine men were employed on that date. Clay is mined by 
hand m an open pit and hauled in a small truck to the railroad cars, a few hundred 
feet away. It is thought this clay will prove suitable for tile. The white sand is 
stated to run 71% silica. If regular production starts, drifts will be .run to avoid 
handling the overburden." 

1 State Mineralogist's Rep. XXIII, p. 141. 



62 



DIVISION OF MINES AND MINING 




CLAY RESOURCES AND CERAMIC INDUSTRY 63 

Three samples were taken from tliis property. No. 129 is sand 
from the upper sand bed, taken from the nnderjifround -workings at 
the Avorking face when visited on August 8, 192,"). The test results are 
given on page 2()1. Sample Xo. ].'}() is representative of the carbonaceous 
sand, and was taken with the object of studying possible uses. The 
test results, page 2!H), on tlie untreated sand were nnfavoi-abh'. and is 
unlikely that beneficiation, even if proved possible, would be of com- 
mercial importance in the immediate future. Sample No. 131 is from 
the deposit of red clay from the new pit, and is seen (p. 329) to be quite 
similar in its jiroperties to the Bacon red (sample No. 127. p. 335). 

Yosemite Portland Cement Company.^ Main office. Pacific Building, 
San Francisco. This is known as the Harvey ])it and is part of over 
100 acres of land recently purchased from Fred Harvey. The pit is 
just east of the old Ilarvev coal mine, and one mile north of Carbondale. 
The land is in Sees. 32, 33 et al., T. 7 N., R. 9 E., M. D. M. 

Bluish fireclay occurs with an overburden of from two to three feet 
of soil in which are found concretionary boulders of red iron oxide. 
The pit was formerly operated by hand methods, but in 1927 a jViow 
and scraper, drawn by a tractor, were used for removing the over- 
burden, and the clay was mined by a small steam shovel. The pit is 
now about 12 feet deep, and it is stated that borings have indicated 
a depth of 65 feet of clay, over an extensive area. Auto trucks are 
used to deliver the clay to the railroad. 

The clay contains about 32% alumina, dry basis, and is used in the 
manufacture of white cement. It is also a useful sewer pipe and 
terra cotta clay. 

Sample No. 133 Avas taken for test. The results are given on page 
298. 

Changes Since Former Reports. 

The following important changes have occurred in the Amador 
County clay industry since the publication of Preliminary Report 7, 
and the Nineteenth Report of the State Mineralogist : 

Amador Kaolin Company. Extinct. 

W. D. Amirk Property (formerly operated by the Philadelphia 
Quartz Co.). A white sand deposit containing from 20% to 30% of 
kaolin. A washing plant was built and operated during the World 
War. Now dismantled and idle. 

McKissick Cattle Company. Former owner of Rancho Arroyo Seco, 
now ow^ned by S. E. Kieffer and leased by U. A. Starkweather, as noted, 
ante. 

Newman Clay Company. Now ]\Iay E. Newman Estate. 

Philadelphia Quartz Company. No longer operating in the county 

Bibl. of lone district : Cal. State Min. Bur. Report XIV, pp. 5-11 ; 
XXIII, pp. 134-144. Bull. No. 38, p. 206. Prel. Rept. No. 7, 
p. 38. 



' Logan, C. A., op. cit., p. 138. (Under Pacific Poi-tland Cement Company, Con- 
solidated.) 



64 DIVISIOX OF MINES AND MINING 

BUTTE COUNTY. 
General Features. 

Butte County is in the north-central jiortion of the state, lar<iely 
between the Sacramento and Feather rivers. Its -western half is in 
the Sacramento River basin and its eastern half is in the foothills of 
the Sierra Nevada ^Mountains. The area of the county is 1722 square 
miles and its population is 30,030 (1920 census). 

Among the mineral resources of the county are asbestos, barytes, 
chromite, gems, gold, limestone, niarbl^, mineral ^vate^, platinum 
group, silver, and miscellaneous stone. The following are produced 
commercially at present: gold, miscellaneous stone, platinum, silver, 
mineral water, brick, coi)per, gems (diamonds), lead, natural gas, and 
soa])stone. 

Clay Resources. 

Deposits of high-grade clay have been reported from numerous local- 
ities in Butte County, especially within a radius of 12 miles from 
Oroville, the count.y seat, but only one of these has been developed. 
Common brick claj's are plentiful at many places in the valley region 
east of the Sacramento River, and northwest of the Feather River, and 
in some of the Neocene River channels at higher elevation. 

Beginning at a point two miles north of Oroville, and extending 
northward for nearly eight miles to Pentz and Cherokee, the lone 
formation has been traced.^ The geologic history of this region has 
been summarized by Lindgren as follows : 

"(1) Deposition of Chico formation (Upper Cretaceous) ; (2) epoch of erosion; 
(3) accumulation of lowest gold-bearing gravels (Eocene?) ; (4) deposition of lone 
formation, underlying Table Mountain; (5) eruption of basalt of Table Mountain; 
(6) formation of high volcanic gravels of Table Mountain; (7) epoch of erosion; (8) 
deposition of tuff and lower gravels (late Pliocene) of Oroville; (9) epoch of erosion; 
(10) deposition of bench gravels of Oroville (Quaternary); (11) epoch of erosion; 
(12) deposition of present stream gravels. The epoch of erosion (item 7 above) fol- 
lowing the formation of the high volcanic gravels in many places removed a part of the 
lone formation and basalt before the deposition of tuff. The lone formation itself 
was laid down on a very uneven surface." 

As a result of the foregoing geologic lii.story, it is possible that many 
of the occurrences of high-grade clay that have been reported are small 
and irregular, although in most localities thorough prospecting by 
drilling will be necessary in order to determine the size, shape, and 
quality of the deposit, as very little information can be gleaned by 
surface examination. So far as known, the only property in the Tone 
formation that has been well prospected is that of the Table ^Mountain 
Clay Products Co. near Wick, where a sufficient quantity of good clay 
was found to warrant the erection of a plant. 

A number of localities south and southeast of Oroville were investi- 
gated, and samples were taken of some of the typical materials of pos- 
sible ceramic utility. Some of these proved to be derivatives of the 
rhyolitic and andesitic flows, with little or no ceramic value. The 
nature of such deposits is discussed more fully in the descriptions of 
depo.sits in Nevada and Placer counties. 

Some clay from settling-ponds left by the dredges that formerly 
operated near Oroville has been mined and shipped to various ceramic 
plants, especially to the Gladding, McBean & Co., plant at Lincoln, 

> Lindgren, Waldemar. The Tertiary Gravels of the Sierra Nevada of California : 
Prof. Paper 73, U. S. Geol. Survey, p. 86, and Plate XV, 1911. 



CLAY RESOURCES AND CERA^MIC IXDTTSTRY 65 

l*lacer County, but the new (■iit('r])i'isc of the Natonia Clay Co., at 
Xatonia. Sacramento County (see pa<re lS(i), will doubtless render sueli 
operations nni)J'ofital)le in Oroville. 

One common l)riek plant near Palermo sui)plies the needs of tliis 
region for common buildin<? brick. 

The Lund Brick Yard is on the Nelson E. Lund ranch, .3.6 miles 
by road east of the Palermo-IIoncut road from a point 4.4 miles south- 
east of Palermo, a total of 13.7 miles by road southeast from Oroville. 
At the time of visit, on August 24, 1925, the first successful burn of 
common red brick had been completed. Mr. Lund expects to manu- 
facture ruffled face brick if the local demand warrants. 

The clay is mined by hand methods from a deposit of clay and silt 
that comprises the upper i)art of a Tertiarj^ river channel deposit, 
parts of which were formerly hydraulicked for gold. Three distinct 
variations of sand-gravel-clay beds are exposed in the pit. The upper 
bed is from one to three feet thick, and consists of fine-grained red- 
colored plastic cla}', with little sand and few pebbles. Tlie middle 
bed contains more sand, and some fine gravel, and is from three to 
four feet thick. The lower bed, of unknown thickness, is too sandy 
to work alone, and contains considerable fine gravel, and some larger 
boulders. Each of these beds was sampled separately, under the sample 
numbers 178-, 1, 2, and 3, respectively, from the top down. The middle 
bed gives the best results for brick-making and the top bed is character- 
ized by high shrinkage and danger of cracking during drying and 
firing. A reasonably uniform product can be obtained by inelutling a 
sufficient proportion of the sandier bottom bed to offset the high shrink- 
age of the top bed, but on account of extreme and sudden variations in 
the character and thickness of each of the beds, this may be difficult 
unless a method of bedding and reclaiming is used in the plant. See 
page 325 for the results of test. 

Tlie plant is equipped with a bucket elevator for delivering the 
material from the pit to a roll cruslKM-. This is followed by double 
pugging, and an auger machine of 2(),()U0 brick daily capacity. Power 
is supplied by steam from an oil-fired boiler. The clay is worked in a 
softer state than is commonly used with auger machines. Drying is 
done under sheds. Care must be taken to avoid ex])osure of the brick 
to sun and hot wind during drying, as serious drying cracks may 
develop. 

An oil-fired kiln is used for firing. Steam is used for atomizing the 
oil. In the 10-ft. by 20-ft. kiln in use at the time of visit, the firing 
required seven days, and the kiln cooled in four to five days. 

The plant is operated as needed to supply the local demand. 

Table Mountain Clay Products Co. L. F. Riley, president; H. M. 
Gamble, superintendent. Home address, Oroville. This company has 
acquired and developed a clay deposit in the SW|- of Sec. 22, T. 20 N., 
R. 3 E., ^I. D. ]\L, and at the time of visit on August 24, 1925, were 
constructing a plant for the manufacture of face brick, hollow tile, 
and roof tile. The plant lies 0.4 mile w^est of the Oroville-Pentz high- 
way, from a ]ioint 5.9 miles by road northwest from the center of 
Oroville. 

The property was prospected by means of auger holes, most of which 
varied from 14 to 22 feet deep. Clay was found under a large portion 

5—54979 



66 DIVISION OF MINES AND MINING 

of the property, underlying a A-ariable amount of basaltic cappinf?. 
None of the holes penetrated to the bottom of the clay beds, and it is 
claimed that one hole was drilled to a depth of 72 feet without 
encounterinji: a change of formation. 

The overburden coverino- a large portion of the area is only 6 inches 
to 2 feet in thickness, and mining operations will at first be confined 
to this ground. Mining is done with horse scrapers, delivering the clay 
to belt conveyors which are extended as the pit advances. 

The clay is crushed in rolls, mixed in a pug-mill, and the products are 
shaped on an auger-machine having a capacity of 40,000 brick per day. 
A dry pan may later be added ahead of the pug-mill. Drying is done 
under sheds in the open air. The kilns are fired with oil. 

►Sample Xo. ITo was taken for test, the results of which are on page 
304. 

Undeveloped Deposits. 

Two samples were taken from alongside the Oroville-Quincy road. 
No. 176 (see page 825) is a decomposed igneous rock, considerably 
kaolinized, and badly iron-stained, from an exposure 4.3 miles by road 
southeast from the center of Oroville, in Sec. 13, T. 19 N., R. 4 E., 
M. D. M. The sample probably contains more iron oxide than would 
be found in the body of the deposit. The size of the deposit could not 
be estimated, but the occurrence is such as to indicate a good tonnage. 
The material is suitable for the manufacture of red brick. Another 
sample, No. 177 (see page 336), was taken from a road cut, 2.9 miles 
from the center of Oroville. It is high in volcanic ash, but contains 
enough alluvial clav and silt to make it usable to a limited extent in 
the manufacture of red brick, if mixed with a more })lastic clay. The 
extent of the dei)osit was indeterminate. 

An unsuccessful attempt was made to secure recent information 
regarding the deposits mentioned in previous reports of the Bureau.^ 
All of these reports were made previous to 1906, and in the limited 
time available for the present investigation, it was impossible to find 
anyone in the various localities mentioned who had any knowledge of 
the existence of clay deposits, or who were able to give information 
regarding the former ow^ners of these deposits. For the sake of com- 
pleteness, these reported occurrences are listed hereunder, wuth such 
notations that seem of interest at the present. 

Bohannon Ranch, Yankee Hill. Sec. 4, T. 21 N., R. 5 E., M. D. M. 
"Large body of plastic yellow clay, tenacious and refractory." This 
lies in the Big Bend of the Feather River, probably at an elevation of 
over 1000 feet above the bottom of the canyon. If of economic value, 
clay could be delivered by pack-train or tramway to the Western Pacific 
railroad, a distance of probably two miles. The result of inquiry 
among residents of Yankee Hill did not warrant an attempt to find 
the property. The mere fact that it was described as "yellow," and 
that it is in such an isolated region preclude the possibility of economic 
utilization for many years to come. 

Biggs. (Max Brooks and Mr. Reed, reported owners). Sec. 19 and 
30, T. 18 N., R. 3 E., "Light brown and wdiite, brittle clay, about 

' Cal. State Min. Bur. Prel. Rept. No. 7, p. 43, which summarize.s the data given in 
Bulletin No. 38, p. 211. 



CLAY RESOURCES AND CERAMIC INDUSTRY 67 

one-half mile wide." This is now included in the Butte County Farms. 
Mr. II. II. ({rimos, tli(^ luanapTr, kindly uiidoTtook an inquiry amono: 
old-time residents and employees in the vicinity, and re])orted tliat 
nothing: was known of such a deposit, and that the previous report 
may have referred to a wide belt of hard-pan that comes close to the 
alluvial surface of the ground over portions of the property. 

Coal Canon. Sec. 12, T. 20 N., R. 3 E., "A stratum of clay in a 
coal mine." This probably refers to an abandoned and inaccessible 
coal mine in the lone formation nnderlyinp- Table ^Mountain. The 
property is 2.5 miles northeast of the i)lant of the Table Mountain 
Clay Products Co. 

Durhin Ranch. SWj Sec. 13, T. 21 N., R. 3 E., "Large deposit of 
refractory clay, with low ])lasticity. Total dei>th 100 ft." Also, 
"* * * a deposit of light-colored clay, more plastic than above in 
XEj, Sec. 13." This would lie one mile north of Pentz. A recon- 
naissance of this section was made, without finding any material of 
value. Most of the section is covered with Tuscan tuff. The lone for- 
mation outcrops to the south, and disappears under the Tuscan tuff. 

Garden Ranch. SWj Sec. 22. T. 19 N., R. 3 E., 3 miles southeast 
of Oroville. "Extensive deposits exposed in road building." No 
material of value could be found on this area. 

Snow Ranch, Lovelocks. SWj Sec. 31, T. 24 N., R. 4 E., "Light- 
colored clays of medium plasticity." A reconnaissance of this locality 
was made, and nothing of interest was found. Some partly kaolinized 
diabase ( ?) occurs in ])laces, but is badly contaminated with iron. The 
region is too inaccessible to be of economic importance as a producer 
of any but the finest grades of clay. 



CALAVERAS COUNTY. 
General Features.' 

Calaveras County lies on the west slope of the Sierra Nevada Moun- 
tains, the elevation ranging from 400 feet above sea level, where it joins 
San Joaquin County on the west, to 8000 feet where the eastern bound- 
ary rests on the summits of the Sierras adjoining Alpine County. 
Bounded on the north by Amador County and on the south by 
Tuolumne, it shares with them the advantage of a climate where snow 
seldom falls and practically never lies below 2500 feet elevation, and 
where mining may be carried on throughout the j'ear under ideal 
weather conditions. 

Water, power, and timber resources are plentiful. Several railroad 
branches connect the main towns with points in the San Joaquin Valley. 
Most points in the county at elevations under 2500 feet can be reached 
by automobile during the greater part of the year. 

The principal mineral .products of the county are gold and copper. 
Other minerals that have been produced are silver, produced as a 
by-product of gold and copper mining, limestone, mineral paint, clay, 
mineral water, asbestos, rock crystal (quartz), chromite, and miscel- 
laneous stone. 



'Prom Logan, C A., Calaveras County: State Mineralogist's Report XXI, p. 135, 
1925. 



68 DIVISION OF MINES AND MINING 

Geology. 

The geoloyy of the county is similar to that of Amador County and 
others in the Mother Lode belt. The lone formation (Eocene) is found 
at numerous places, but is not so extensively developed, nor so well pre- 
served as in Amador County. The following is a portion of the 
geological summary of the county as given by Logan :^ 

"The Neocene shore-line, as Indicated by the lone formation, covered the county 
from Lancha Plana through Valley Spring to .Jenny Lind, and southward to Milton. 
The most westerly of the lode mining districts are the Hog Mountain-Gopher Range 
cojiper mining district, where copper ores occur in diabase and allied rocks, near 
the southwest corner of the county, and the Campo Seco copper district, where 
similar ores occur in amphibolite schist. In a depression called Salt Spring Valley, 
between the older crystalline rocks of Gopher Ridge and Bear Mountains, lies a 
belt of black Mariposa slate with interbedded lenses of ami)hibolite, with important 
copper deposits, which conform in strike with the direction of schistosity of the enclos- 
ing rocks. The Mother Lode belt of black Mariposa slate enters the county at 
Middle Bar, but aside from the Gwin Mine, which had reached a depth of 2Sr)0 feet 
before it was closed several years ago, little deep mining has been done in this 
district, though numerous quartz mines have been opened to depths of less than 1000 
feet. There are many ijrominent veins in the granodiorite area of Mokelumne Hill, 
but the main belt passes southeast, a line of Assuring having passed into the amphib- 
olite schist, in which rock were found the deep mines of Angels Camp and Carson 
Hill. 

"The East Belt is a general name given to the gold-quartz mining districts in the 
great body of Calaveras (Carboniferous) rocks, lying east of the younger Mother 
Lode slate and east of the amphibolite schists accompanying the Mariposa slate. 
The Calaveras rocks are chiefly hard blocky siliceous and micaceous schists, quartzite, 
curly black slates and accompanying intrusive dikes, usually of basic character." 

Clay Resources. 

Various clay deposits in the lone formation near Valley Springs and 
Helisma have been operated in the past. Some work has been done 
recently on a deposit of kaolinized talc schist in the Calaveras (?) 
formation. 

The California Pottery Co.y of Oakland and IMerced, own two deposits 
in Calaveras County, one at Nigger Hill, and the other at Valley 
Springs. Henry Ward of Vallej^ Springs is superintendent. 

Nigger Hill : Near Nigger Hill, about three miles north of Valley 
Springs, a good deposit of white-burning kaolinized sericite schist has 
been discovered. A tunnel has been driven for 250 feet. The kaolin- 
ized zone is from 15 to 25 feet thick. The material has low plasticity, 
but is of use as a filler in white tile bodies. 

Sample No. 236 (p. 263) was taken at the face of the tunnel, and 
Sample No. 237 (p. 263) was taken at the portal. 

Valley Springs Clay Pit : This pit is ^ mile northwest from Valley 
Springs on a spur track from the Valley Springs branch of the Southern 
Pacific Railroad. The property comprises 17 acres. Fireclay from the 
lone formation is mined from an open pit, shown in photo No. 11. Two 
distinct varieties of clay are mined and shipped to the Merced plant of 
the companj'. One of the.se is classed as 'pink mottled,' (sample No. 
202. ]). 337), and the other is 'yellow' (sample No. 203, p. 337). The 
two varieties are somewhat intermingled, but can be separated by 
hand as mined. In the southern end of the pit, northward to the 
break in the face shown in the photo, the pink mottled predominates, 
and in the northern end of the pit, the yellow variety is more important. 
Some yellow sandy streaks traverse the clay, and in places small 
quantities of white claj^ are found. 

' Ov. fit., p. 140. 



CLAY RESOURCES AND CERA:MIC INDUSTRY 



69 



The floor of the pit is approximately 200 ft. square, and the face 
varies from 10 to 30 feet high. The clay is loosened by hand drillinp; 
and light blasting, and is loaded by hand shoveling into ■wlicolbarrows, 
"which are dumped into a hopper. An inclined belt conveyor trans- 
ports the clay from the hopper to a railroad car. 

In a test pit five feet deep, just east of the track, ])ink mottled clay 
is exposed. Fifty feet farther east another test-]iit was snnlc, Avitli the 
aid of a Avindlass, to a doptli of 25 feet. Uoth i)iidv-mottled and yellow 
clay were found to the bottom of the shaft. From the debris surround- 
ing the collar of the test-pit it was estimated that the pink-mottled 
variety comjirised about one-third of the material excavated. A third 
25-ft. test pit was dug 100 feet north of the second one, and similar 
material was encountered, in addition to a bluish-white plastic clay, 
not entirely free fioin liiiionitie stains (sample No. 204, p. 299). This 




Photo No. 11. Valley Springs clay pit (California Pottery Co.), facing west. 
The track runs S. 25° E. The 5-ft. test-pit appears in the center foregi-ound. 
(Samples No. 202-204.) 



test-pit was bottomed in a yellowish sandy bed. From the evidence on 
the dump, the bluish-white variety of clay predominates at this point. 

It is evident that the total thickness of useful clay is in excess of 
50 feet, and the structural and topographic features are such as to 
warrant the expectation that these beds underlie an area of many acres. 

Three men are employed during the operating season. In 1925, nearly 
200 cars were shipped, at the rate of approximately four cars per week. 

Helis'tna Fireclay Depo.'iif. One-quarter mile north of Helisma 
(formerly Burson) station on the Valley Springs branch of the 
Southern Pacific Railroad is an abandoned fireclay pit formerly 
controlled by W. A. Houts, 202 Balboa Building, San Francisco. 
The present ownership of the property was not determined. The 
deposit is in the lone formation. The total thickness of clay exposed 
in the pit varies from 8 to 15 ft. The upper part of the clay bed 
is a bluish-white clay with good plasticity, and the lower part is a 



70 DIVISION OF MINES AND MINING 

greenish-white clay, with less plasticity. Both varieties of clay are 
traversed by thin limonitie seams a foot or more apart. 

The main pit is 150 ft. lonp:, 50 ft. wide and from 8 to 15 feet deep. 
The overburden, of volcanic breccia, increases from a few inches at 
the lower edge of the pit to 10 ft. at the upper edge. Two hundred feet 
to the west is a smaller pit 80 ft. long by 30 ft. wide, and a maximum of 
10 ft. deep. The clay is similar to that in the larger pit, but contains 
more iron, and is more sandy. 

The clay was formerly worked by hand loading into cars which were 
hauled up a gentle incline to a loading chute overlooking a railroad 
siding. All equipment has been removed from the property. 

The probable extent of the clay bed beyond the existing exposures 
could not be determined without boring, on account of the overburden. 
Structural features are favorable to a continuance of the clay under the 
low hill on which the pit is located, but the overburden covering the top 
of the hill may be 20 ft, or more in thickness. 

Sample No. 201. page 305, includes both types of clay from the 
main pit. 

Bibl : Cal. State Miu. Bur. Prel. Kept. No. 7, p. 43. 

Pcnn Mining Co. During the operation of the copper smelter at 
Campo Seco, a kaolinized sericite schist overlying the copper beds was 
used in the smelter as a refractory. Since the smelter was closed down 
this material has not been utilized. The locality was visited on Septem- 
ber 22, 1926, and a sample was taken from the abandoned open cut 
from which it was formerly obtained. The sample is Xo. 238 and the 
tests demonstrate that the plasticity and strength are low, and that the 
content of fluxes is high, causing fusion to begin at cone 9 (1285° C). 
See page 316. 

Bibl: State Min. Bur. Bull. 38, p. 211 ; Prel. Kept. 7. p. 43. 

Texas Mining Compan}/. J. P. Hoskinson, Valley Springs. This is 
an undeveloped property about two miles north of Valley Springs. 
Small exposures of sandy fireclay belonging to the lone formation have 
been found, and some prospecting has also been done on an outcrop of 
kaolinized sericite schist of Calaveras (?) (Carboniferous) age. Sample 
Xo. 233 was taken of the fireclay, but was not tested, as the quality was 
obviously poor, and the continuity of the deposit is doubtful. Sample 
No. 234 and 235 were taken from two different exposures of the kaolin- 
ized schist. The test results of X"o. 235 are given on page 263. It is a 
white-burning refractory material of low plasticity, that would be 
useful as a filler in white ceramic bodies. X'^o. 234 wa.s not tested, as it 
is similar to No. 235. 

COLUSA COUNTY. 
General Features. 

Colusa County lies on the west side of the Sacramento Valley. The 
west side of the county is in the foothills of the Coast Range, and the 
east side is in the basin of the Sacramento Valley. The area of the 
county is 1140 square miles, and the population is 9920 (1920 census). 
Colusa is the county .seat and principal town. 

The mineral resources of (^olusa County are largely undeveloped. 
Occurrences of coal, chromite, copper, gypsum, manganese, mineral 



CLAY RESOURCES AND CERAMIC INDUSTRY 71 

•water, ])yrite. ciincksilver, sandstoni', iiiiseellaneous stone, sulplnir. and 
in some places, <i:ol(l and silver, are known. Of these, the only commer- 
cial production is of minei-al water, sandstone, and miscellaneous stone. 

Clay Resources. 

Common clays suitable for the manufacture of brick are abundant, 
but there is at present no local industry. A bi'iek yard was at one 
time operated at Colusa by George Smith. 

Bibl: State Mineralogist's Kept. VIII, p. 15!); State Min. Bur. 
Bull. 38, p. 242 ; Prel. Kept. 7, p. 44. 



CONTRA COSTA COUNTY. 
General Features.' 

Contra Costa is one of the East Bay counties and is bounded on 
the west and north by the waters of San Francisco, San Pablo and 
Suisun bays and San Joaquin River. San Joaquin County is on the 
east and Alameda County is on the south. 

The area of the county is 714 square miles, about half of which is 
under cultivation. The population in 1920 was 53,889. Its industrial 
and sliipping activities are extensive. The county has approximately 
70 miles of deep w'ater-front on which are located nine port cities in 
whicli have been established many chemical and industrial woi'ks. 
Agriculture, stock raising, and to a le.sser extent, mining, contribute to 
the prosperity of the county. 

Topographically, Contra Costa County is distinguished by containing 
tlie most prominent landmark in the central coast counties, Mt. 
Diablo, which rises to an elevation of 3849 feet above sea level. This 
peak is in the eastern part of the two main ridges of the Coast Range 
Mountains, which strike northwesterlj' across the county. The western 
ridge lies close to the coast. Its crest is more regular but its highest 
peaks are less than 2000 feet in elevation. The western flank slopes 
gently towai'd San Francisco Bay. Between the eastern and w^estern 
ridges lies San Ramon Valley, drained by San Ramon Creek, which 
flows northward into Walnut Creek and hence into Suisun Bay. 
Marsh Creek rises on the eastern slope of Mt. Diablo and tlow's north- 
easterly into the San Joaquin River. These are the two principal 
streams in the county. The northeastern corner of the county is 
included in the delta area of San Joaquin Valley and is elevated only 
slightly above sea level. 

Geology. 

Tliat portion of the Coast Range within Contra Costa County has 
been studied by the Department of Geology and Paleontology of the 
T^niversity of California, and the soutlieastern portion has been mapped 
by Lawson.- 

A nearly complete section of the Coast Range formations from the 
Franciscan to the recent are exposed within the county, but as the area 
is one of many faults, no single formation is continuous over a large 

' From Laizure, C. McK.. Contra Ccsta Countv : State Mineralogist's Rept. XXIII, 
p. 2. 1927. 

- Lawson, A. C. San Francisco Folio, No. 193, U. S. Geol. Survey. 



72 



DIVISION OF MINES AND MINING 



area. The most abundant strata are sandstones and shales of Cretaceous 
and Tertiarj^ age. 

Contra Costa County is lacking in deposits of valuable metals, but 
its structural materials are important natural resources on account of 
their easy accessibility and proximity to the cities surrounding San 
Francisco Bay. Its coal deposits are of potential value. The most 
im]K)rt;int minerals now produced are : cement, miscellaneous stone 
(crushed rock, sand, and gravel), and brick. Claj', limestone, mineral 
water, and foundry sand are also on the commercial list. Other mineral 
resources include asbestos, coal, copi)er, diatomaceous earth, manganese, 
and quicksilver. 

Clay Resources. 

Alluvial clay and silt are not abundant in those parts of the county 
that are favorably situated with respect to manufacturing and market- 
ing conditions. However, there is an abundance of Tertiary clay shale 







Photo No. 12. California Art Tile Co. plant, Richmond, Contra Costa County. 
(From State Mineralogist's Report XXIII, p. 7, 1927.) 

in several of the formations that are widespread throughout the area, 
and a number of brick and hollow-tile plants have been established at 
various places. 

No deposits of high-gi*ade clays have thus far been discovered in the 
county, but on account of favorable manufacturing and marketing con- 
ditions, a number of important ceramic ])lants have been established in 
or near Richmond, and a wide diversity of ceramic ware is produced. 

California Art Tile Coinparni. J. W. Hislop, ]3resident ; L. J. Hislop, 
secretary; W. A. Hislop, chemist; and C. E. Cummings, superintendent. 
Address, Box 1116, Richmond. This plant is at Twentj^-seventh and 
Maine streets, Richmond, and was built in 1926 to replace a smaller 
plant that had been established in 1922. Decorative wall and mantel 
tile are made from a buff-burning fireclay body, and terra cotta glazes. 
Lincoln clay and lone sand are used for the body. A view of the plant 
is shown on Photo No. 12, 



CLAY RESOURCES AND CERAMIC INDUSTRY 73 

The body mix is ])repared by grinding in a 10-ft. dry pan, followed 
by a pug-mill. A tile auger with a patented cutter is used for making 
the regular sliapes. and special shapes are hand pressed. Drying is 
done in a room heated by kiln gases. The glazes are applied by spray- 
ing before firing. Saggers are made at the plant in a sagger press. 

The kiln equipment consists of three 30-ft. and one 24:-ft. oil-fired, 
round down-draft kihis. The tile are fired to cone 8 to 10 in four days. 
The cooling time is also four days. 

Forty men are employed at the plant. The rated output of the 
plant is 40,000 sq. ft. of tile per month. 

Bibl: State Mineralogist's Report XXIII, p. 7, 1927. 

N. Clark and Som. At 0x1 ey siding, on the Southern Pacific Rail- 
road, i mile north of Walnut Creek, is a shale pit owned by N. Clark 
and Sons. 116 Natoma Street, San Francisco. The material is a thin- 
bedded, soft, nearly white, calcareous shale of Tertiary age (Miocene?), 
overlain unconformably by sand and gravel. It is used as a component 
of terra cotta and other mixtures in the company's plant in Alameda. 

The deposit is Avorked by an open cut along a face that is approxi- 
mately 200 feet long. At the southern end of the pit, the shale bank is 
70 to 80 feet high above the floor of the pit, but the contact between the 
shale and tlie overlying gravel and sand dips toward the north, so that 
tlie shale disappears at the northern end of the pit. The shale is broken 
by hand drilling and blasting, and is delivered to a loading platform 
eitlier by wheelbarrows or by horse-drawn scraper. A storage shed 
is provided for the winter supply when mining is stopped. Sample 
Xo. 200 was taken for testing, tlie results of which are on ]iage 342. 

]Mr. Faber of Walnut Creek is mining under contract, and two or 
tliree men are employed during the operating season. About two cars 
])er week are shipped. 

Bibl : Cal. State Mining Bur. Prel. Rept. No. 7, pp. 44-46 ; State 
Mineralogist's Reports XVII, p. 49, and XXIII, p. 13. 

Mastercraft Tile and Roofing Compan]i. (Entire description by 
Laizure, op. cit., p. 7.) C. V. and F. A. Mero, owners. Office, No. 1 
Twentieth Street, Riclimond. Cement roofing tile has been manufac- 
tured by this company for the past four years at its Richmond plant. 
During the pa.st year (1926) hand-molded clay roofing tile has been 
added to their line. The clay tile plant is on San Pablo Canyon road, 
near San Pablo, but tlie clay is obtained near Richmond. Firing is 
(lone in a rectangular down-draft kiln using oil for fuel. Six men are 
employed. 

Port Costa Brick Co. C. B. Berg, president ; W. S. Hoyt, secretary ; 
B. F. Ferrario, plant superintendent. General offices, 808 Sharon 
Building, San Francisco. The plant is located three-quarters of a mile 
east of Port Costa, at the edge of Carquinez Straits. The products are 
common brick and hollow tile. 

A bank of interbedded bluish shale and red clay of Cretaceous (?) 
age is mined by a 14-yard electric shovel in a large open cut 1000 feet 
from the plant. The clay is transported to the plant in 5f-5^ard hopper- 
bottom side-dump cars, hauled by a gasoline tractor fitted with flanged 
wheels, or by an electric third-rail locomotive. The local material is 



74 ■ DIVISION OF MINES AND MINING 

used alone for the manufacture of brick, but is mixed with one part of 
Lincohi No. 8 (sample No. 148, p. 336) clay for each two i)arts of local 
clay for the manufacture of hollow tile. The Lincoln clay is necessary 
to secure sufficient die lubrication to prevent lamination and rupture 
to the clay as it passes from the auger machine. A sample of the local 
clay was taken for testing. See sample No. 199, i)a<re 326. 

The clays are prepared by grinding in two No. 3 Williams pulverizers 
and three 9-ft. American dry pans. Revolving screens are used to 
remove rock inclusions. The pulverized clay is elevated to bins from 
which it is fed to the auger machines. A special Giant auger machine 
is used for brick, and an American No. 290 auger is used for tile. The 
brick auger is equipped with a Freese cutter, and the tile auger has a 
Chambers No. 5C rotary tile cutter. 

In the summer, some ware is dried in air under sheds. The drier 
yard has a capacity of 1,000,000 brick, and drying is completed in 12 to 
14 days. This method is not used in the winter, when all ware is dried 
in a 22-tunnel oil-fired drier. The drier has a capacity of 400 cars of 
500 brick each, or 200,000 brick, and the drj'ing period varies from four 
to six days. The dryer heat is supplied by an oil furnace, using Ray 
burners. Two 25-hp., 66-in. fans, one of which is used as a pressure 
fan and the other as an exhaust, force the heated air through the drier. 

Firing is done in eleven field kilns and a Hoffman continuous kiln. 
The Hoffman kiln has 22 chambers, and has a total capacity of 400,000 
brick. The monthly output of the kibi varies from 1,000,000 to 
1.250,000 brick, wliieli corresponds to a firing cycle of 15 to 18 days, of 
which time 85 to 100 hours is occupied by firing, following the water- 
smoking period. Petroleum coke or coal screenings are used for fuel. 
As a rule, the Hoffman kiln is set to a height of three or four feet from 
the bottom with brick, and then filled with hollow tile. 

Both hollow tile and brick are fired in the field kilns. Tlie local clay 
is tender during the water-smoking period, and coal firing is used 
during this stage, followed by oil during the actual firing period. The 
oil is atomized with steam, Avhich is generated in a 125-hp., horizontal 
fire-tube boiler, equipped with a Johnson rotary oil burner. 

The usual firing temperatures are between 1600 and 1750° F., for 
brick and 1850° F. for hollow tile. 

The plant is operated by electric power from the lines of the Great 
Western Power Co. There is a connected load of about 900 horsepower, 
but only 400 is used at present. Fiftj^ to sixty men are employed. 

Bibl : Cal. State Min. Bur. Prel. Rept. No. 7, p. 45 ; State Miner- 
alogist 's Reports XVII, p. 50, and XXIII, p. 8. 

Richmond Pressed Brick Company. (Described by Laizure,^ supple- 
mented by notes by the author.) The plant was erected by the Los 
Angeles Pressed Brick Company, but it became an independent com- 
T)any, affiliated with the United Materials Company, in 1921. S. 
W. Smith, president ; W. S. Hoyt, secretary ; F. ]\I. Irving, plant super- 
intendent. Home office, Sharon Building, San Francisco. The plant 
is at Point Richmond, near the Santa Fe-San Francisco ferry terminal, 
and is served by a spur track of the Santa Fe Railroad. See Photo 

' Laizure, C. McK., Contra Costa County, State Mineralogist's Rept. XXIII, p. 8, 
1927. 



CLAY RESOURCES AND CERAMIC INDUSTRY 



75 



No. 13. The output includes pressed brick, fire brick, face brick, pav- 
ing brick and red floor tile. 

For the buff and other li-xht-colored brick a portion of the raw 
materials used include clay and sand shipped in from lone and Lincoln, 
as well as some sand from Antioch. Clay shale from the pit adjoining 
the plant is used for making dark-red brick. As the bank is high, the 
material, after blasting, drops largelj^ by gravity to a loading bin. 
From here it is trammed a short distance in cars to the plant. 

Fire brick and most grades of face brick are made by the stiff-mud 
process. Dry pans and a pug-mill are used to prepare the clay for the 
auger machine, which has a capacity of 100,000 brick per day. All of 
the fire brick, and certain grades of face brick are repressed before 
passing to the waste-heat tunnel driers. A specialty of the plant is red 
pressed brick, which is shaped ))> di-y i)ressing, following dry-pan 
preparation of the clays. 




Photo Ko. 13. Richmond I'lessed Urick Co. plant, with clay pit in background, 
Richmond, Contra Costa County. (Sample No. 11 'J.) (From State Miner- 
alogist's Report XXITI, p. 8, 1927.) 



The firing equipment consists of six 36-ft. round down-draft kilns, 
using oil, atomized by compressed air. The red-burned ware is fired 
for nine days to finishing temperatures corresponding to cones 09 to 07 
(930° to 975° C), and the buff face brick and fire brick are fired to 
cones 7 to 9 (1210° to 1250° C.) in seven days. The kilns are equipped 
with pyrometers. 

Electric power is used to operate the plant. Fifty-five men are 
employed. See sample No. 119, page 325. 

Standard Sanitary Manufacturing Company. The Standard Sani- 
tary Manufacturing Company of Pittsburgh, Pennsylvania, purchased 
the plants of the Pacific Sanitary ^Manufacturing Company in 1926, and 
have since constructed a new sanitary porcelain plant, known as Pacific 
Pottery, to replace two smaller plants formerly operated by the Pacific 
company. The Standard company is also continuing the operation of 



76 DIVISION OF MINES AND MINING 

the enameling plant, now known as the Pacific Enamel Works, formerly 
owned by the Pacific company. These plants are in Richmond and San 
Pablo. F. A. Kales, Box W, Richmond, is general manager. 

The two plants manufacture a complete line of porcelain and enameled 
sanitary ware, except porcelain bath tubs. Both plants are modern in 
every respect, and are designed for economy of production and close 
control of manufacturing methods to ensure uniformity of quality. 
Two tunnel kilns were installed in the new porcelain ])lant. 

It is against the policy of the company to permit ])ublicati()n of 
details regarding the plant equipment and operation. 

Bibl : State Min. Bur. Prel. Rept. 7, p. 44, 1920. 

Extinct Companies. 

Among the former brick companies that have ceased operations in 
the county are : 

Mt. Diablo Pottery and Paving Brick Co. 

Carquinez Brick and Tile Co. 

Coast Firebrick Co. 

Holland Sandstone Brick Co. 

Diamond Brick Co. 

Golden Gate Sandstone Brick Co. 

Richmond Brick Co. 

Gerlack Brick Co. 

DEL NORTE COUNTY. 
General Features. 

Del Norte County, in the northwest corner of the state, is without 
rail connections, and is dependent upon light-draft vessels docking at 
Crescent City, auto stages, trucks, wagon and pack trains for trans- 
portation. Lumbering is the principal industry. ITnder such condi- 
tions, and with a population of less than 3000 (1920 census), the 
demand for clay products is so small that practically no clay industry 
has been developed, and no deposits of high-grade clay have yet been 
found that will warrant mining and shipment to outside points. 

The geology and the physiographic features of the county have been 
well summarized by Laizure : ^ 

"A low costal plain, three to five miles in width, extends from the vicinity of Smith 
River to a point a few miles south of Crescent City. East of and surrounding this 
area of Quaternary formations and extending- from the Oregon line through Del Norte 
and south into Humboldt is a belt of Franciscan rocks, mainly sandstones and shales. 
The eastern boundary of this belt crosses Smith River just west of South Fork, and 
its contact with the succeeding zone of metamorphic and eruptive rocks marks the 
line between the Coast Range and the Klamath Mountains. This succeeding zone of 
metamorphics also extends through the county from north to south, widening out 
toward the north, where its width is about 15 miles. It is composed mainly of 
serpentine with unaltered masses of peridotite and many inclusions of 'diorite,' more 
or less altered. This belt is mineralized and most of the deposits of gold, copper, 
chromite, and platinum are associated v\ith it. Between here and the eastern bound- 
ary there is another narrow belt made up largely of Franciscan schist and slate, 
intruded by deep-seated igneous and volcanic rocks. Serpentine again predominates 
along the boundary and extends over into western Siskiyou County." 

Clay Resources. 

Deposits of common clay suitable for brick manufacture occur at 
several points within a short distance of Crescent City, especially in 

^Laizure, C. McK., Del Norte County: State Mineralogist's Report XXI, p. 282, 
July, 1925. 



CLAY RESOURCES AND CERAMIC INDUSTRY 77 

Elk Valley and along the Smith River. A small brick yard, ^vitll a 
wood-tired kiln, was at one time ojx'rated by licnjmnin llowbind, wlio 
used clay from the ]Musiek i)roperty. in P]lk Valley, 4.8 miles from 
Crescent City.' There is said to l)e a deposit of good pottery clay in 
Elk Valley,- hut this could not be verified in the course of the present 
investigation. 

Musick Properixj. This proi)efty lies ().:{ nule north of the Elk 
Valley road, from a point 4.5 miles from the center of Crescent City. 
The pit, now abandoned, is 25 feet in diameter, and three to four feet 
deep. A laj-er of black soil, less than one foot deep, overlies a yellow 
plastic clay, of unknown thickness and lateral extent. 

Sample No. 180 was taken from this deposit. The test results are 
on page '-Vl^. 

FRESNO COUNTY. 
General Features.' 

Fresno is one of the southern counties of the San Joaquin Valley. 
Madera and Pierced counties are on the north, Mono and Inyo on the 
east, Tulare and Kings on the south, and San Benito, Monterey and San 
Luis Obispo on the west. The area of the county is 5977 square miles, 
or nearly three times that of the State of Delaware. The population 
is 128,779 (1920 census). The San Joaquin River separates Fresno 
from ]\Iadera County, and the eastern boundary runs along the summit 
of the Sierra Nevada Mountains. Along this line are nnmemus peaks 
exceeding 1:^,000 feet in elevation above sea level. 

Adequate transportation is provided throughout the populous sec- 
tion of the county by two railroads — the Southern Pacific and the Santa 
Fe — each of which has many branches to important points. Power and 
water facilities are well provided for mining, industrial, and agricul- 
tural i)urposes. 

The ])rincipal wealth of the county is in agricultural products, and 
the greater i)art of that portion of the county lying in the San Joaquin 
Valley is under cultivation. The most important mineral i)roduct is 
petroleum, the bulk of which is produced from the Coalinga field, and 
is responsible for placing Fresno County sixth in importance as a 
mineral i)roducer among the counties of California. Miscellaneous 
stone is of secondary importance. Other commercial products are nat- 
ural gas, granite, brick and hollow tile, gold and silver, and mineral 
water. Comparatively little mineral development has been done in the 
mountainous portion of the county, but occurrences of many useful 
minerals other than those noted above are known, among which are 
asbestos, barytes, chromite, copper, gems, graphite, gypsum, limestone, 
magnesite, marble, quicksilver, and tungsten. 

Clay Resources. 

No commercial deposits of high-grade clays have been discovered in 
the county. The alluvial silts of the San Joaquin Valley have been 
utilized for numy years for the manufacture of common brick and 
hollow tile. There is, however, a scarcity of common clay of suitable 
plasticity for this purpose, and it has often been necessary to ship in 

' State Mineralogist's Report XIV, p. 379, 1913-14. 

- Idem. 

= See State Mineralogist's Rept. XIV, pp. 429-432, 1914. 



78 DIVISION OF MINES AND MINING 

small (|iiantities of this material to the brick yards from distant points. 
Two brick plants are at present (1927) in operation, one of which makes 
hollow tile and face brick in addition to common brick. 

Craycroft-HcroJd Brick Co. F. J. Craycroft, president, 407 GrifSth- 
McKnig"ht Building-, Fresno; Wm. Turner, vice president and superin- 
tendent. The plant is located at Crayold siding three miles west of 
Fresno. The products are common brick, ruffled and plain face brick, 
and hollow tile. 

Some of the clay used in the plant is from a superficial valley deposit 
of plastic clay 6 miles south of Merced. The deposit is mined to a 
depth of 14 feet, and one car (50 tons) per day is used to mix with a 
local clay from a pit near the plant. The local clay is mined to a depth 
of five feet with a horse scraper. It is a valley silt, with insufficient 
plasticity to be used alone. 

The plant is equipped with a 9-ft. dry i)an and revolving screen for 
preparing the tile mixture, and a No. 4 Williams pulverizer for the 
brick mixture. The ground mixture is elevated to bins from which it 
is fed to the pug-mills by automatic feeders. An American No. 2 auger 
is used foi" tile, and an American No. 4 auger with a Freese cutter 
shapes the brick. Drying is generally under sheds, as under the pre- 
vailing conditions the waste heat drier with which the plant is equipped 
has insuf^cient capacity, and o]ierating costs are higher than open-air 
drying. In the summer, when the atmosphere is hot and dry, the ware 
is dried in about seven days. 

The face brick are fired in three 38-ft. round down-draft kilns. 
Common brick and hollow tile are fired in field kilns, having a capacity 
of 950,000 common brick each. The fuel is oil, atomized wuth steam. 
The firing period is 7 days, to a temperature of 1900° F., followed by 
7 days cooling. Pja-ometers are used to control the temperature of 
the down-draft kilns. 

The capacity of the plant is 56,000 brick and 6,000 hollow tile per 
day. Electric power is used throughout the plant. 

Bibl: State Mineralogist's Report XIV, pp. 433-434; Bull. 38, 
p. 242. 

Pioneer BricTc and Tile Company. T. W. Hasty, president and 
manager; Arthur Bentley, superintendent. Address P. 0. Box 614, 
Fresno. The plant is at California and Peach avenues, south of Fresno. 
Common red brick is the only product. 

A local valley clay is used, and it is mined to a depth of five feet with 
a Bay City gasoline shovel. Hardpan underlies the clay. The clay is 
delivered to a Potts disintegrator, from which it is carried by a belt 
conveyer to a pug-mill, followed by a Bonnett auger, equipped with a 
Freese cutter. The brick are dried in sheds, requiring from seven to 
ten days. Three open kilns are in use, fired with oil, atomized with 
steam. The kilns have a capacity of 1,060,000 brick each. The firing 
period is 5^ to 6 days, to a maximum temperature of 1550 to 1600° F., 
and cooling requires 4 to 5 days. One and one-half barrels of oil are 
used per thousand brick. 

The capacity of the plant is 40,000 brick per day. Electric power is 
used for all machinery. 



CLAY RESOURCES AND CERAMIC INDUSTRY t)f 

GLENN COUNTY. 
General Features. 

Glenn County lies on the west side of Sacramento Valley, north of 
Colusa, and south of Tehama. Its area is 1259 scpiare miles, and the 
population is 11,8;53 (1920 census). Willows is the i)rincipal town. 
The western portion of the county is in the foothills of the Coast Range, 
and the eastern portion is in the basin of Sacramento Valley. In tlie 
foothills, deposits of chromite, coi)per, mang-anese, sandstone, and soap- 
stone have been found. The only couuucrcial mineral production in 
recent j^ears is of sand and lii-avel. 

Clay Deposits. 

Brick clays are abundant, especially in T. 19 and 22, R. 8 W., M. D. M. 
The clays are chiefly sandy loam. No brick have been made since about 
1895, but several yards Avere operated near Willows previous to that 
time. 

Bibl : State Min. Bur. Bull. 38, p. 243. 



HUMBOLDT COUNTY. 
General Features. 

Humboldt County, of which Eureka is the county seat and principal 
town, is on the north coast, between Del Norte and Mendocino counties. 
Althoup^h the harbor facilities at Eureka are excellent, the progress of 
the county was slow completed through to Eureka from the south. 

The greater part of the country is rugged and mountainous. The 
ridges and spurs of the Coast Range traverse the county in a north- 
westerly direction, roughly paralleling the coast line. The coastal plain 
is narrow and along the greater part of the coast line is practically 
nonexistent. 

The area of the county is 1259 square miles and its i)opulation is 
11,853 (1920 census). 

Geology. 

The geology of the county has been summarized by Laizure^ as 
follows : 

"Sedimentary formations extend from the Mendocino County line north along the 
coast to a point about five miles north of Areata. They cover a strip about 12 miles 
wide at the south end. "Where the belt crosses the Humboldt Base Line, the forma- 
tions have a width of 30 miles, gradually running out to a point at the north. In the 
southern part the rocks consist of massive marine sandstones, with some shale and 
limestone beds, all of Cretaceous ago. The northern part is composed of clay shales 
and sandstone of Tertiary age, with small areas of Quaternary sands, gravels and 
clays, notably along the lower reaches of Eel Ri%-er. The eastern boundary of these 
sediments runs a little west of north. The contact on the east and covering all the 
southeastern portion of the county, and extending northwest to Rocky Point above 
Trinidad there is a belt of Franciscan sandstone, chert, and serpentine, about 12 miles 
in width. A long, narrow strip of Cretaceous shales, with lenses of sandstone three 
to four miles wide, borders the Franciscan on the east. It enters the county on the 
southeast at Humboldt Base Line, trends northwest and passes out at Stone Lagoon, 
near Orick. 

"All that portion of the county lying north and east of this belt is composed of 
Jurassic, Paleozoic, and pre-Cambrian metamorphic and intrusive rocks, including 
limestones, schists, slates, extensive masses of serpentine, diorite and other crystalline 
rocks. Most of the gold and copper deposits occur in this area." 



• Laizure, C. McK., Humboldt Countv : State Mineralogist's Report XXI, p. 29.5, 
July, 1925. 



80 DIVISION OF MINES AND MINING 

Clay Resources. 

Common clay suital)l<' for the maiuifricturc of i'e(l-biirnin<i' struc- 
tural ware occurs in sufficient (luantity for the needs of the county 
in the Quaternar}' sediments alonp; the coastal i)lain and main streams. 
Some of the Tertiary formations also contain common clay of good 
quality. Four brick yards liave been operated in the county at various 
times in the past, one at Fortuna, formerly owned by J. D. Thompson,' 
and three in Eureka, known as the Humboldt Clay Manufacturing Co., 
the Tracy Brickyard, and the Eureka Brick and Tile Co. Of these, 
only the last remains in operation, under the name of the Thompson 
Brick Co. 

Pottery clay has been reported in various localities, but none of 
these have yet proved to be of economic importance. A salmon and 
pink-burning clay suitable for making earthernware pottery by the 
easting process has been found on the Angel Ranch, 18 miles from 
Areata, and a few tons per year are used in the ceramic art department 
of the Humboldt State Teachers College. No white-burning clays nor 
fire clays have been reported from the county. None of the localities 
Avere visited where 'pottery' clays have been reported, as the known 
(|uality of the clay was not sufficient to be of economic value when the 
length of haul to possible points of use was considered. 

Angel Ranch Clay. Through the courtesy of Mr. R. H. Jenkins of 
the Humboldt State Teachers College at Areata, who has worked with 
a number of Humboldt County clays, a sample of pink or buff-burning 
pottery clay from the Angel Ranch was secured. The Angel Ranch 
is near Hungry Hollow, on the county road to Hoopaw, and the 
deposit is about 18 miles from Areata, over a fair road. On account of 
the fact that the clay is not of sufficiently high quality to warrant 
commercial exploitation from a deposit at such a distance from cheap 
transportation, the locality was not visited, and little information was 
obtained regarding the extent of the deposit. See sample No. 181, 
page 336. 

Freshivater Slough Beposii. South of Freshwater Slough, near the 
northeast corner of Sec. 36, T. 5 N., R. 1 W., H. j\I. is an exposure of 
grayish white plastic clay in a road cut. The clay exposure is two 
feet thick and 60 feet long, overlain by j-ellowish sandy soil, from 
three to ten feet thick. Boring or test-pitting would be necessary in 
order to determine the extent of the deposit. The material is suitable 
for the manufacture of common brick or hollow tile, as shown by the 
test results, sample No. 18-1, page 342. 

Loofhourrow Deposit. On the property of Dr. T. L. Loofbourrow, 
First National Bank Building, Eureka, four miles south of Eureka, 
and one-quarter mile east of the highway is a deposit of fine-grained, 
excessively i)lastie clay with a bluish-gray color when dry. The age 
of the clay is thought to be Miocene. The clay has been prospected 
by two narrow open cuts, and by numerous hand-auger holes. One 
of the cuts is 50 feet long and the other, near b}^ is 12 feet long. They 
expose the top of the clay bed, which underlies from 10 to 15 feet of 
surface gravel and yellowish clay. It is stated that the auger holes 



' State Mineralogist's Report XIV. p. 392, 1913-14. 



CLAY RESOURCES AND CERAMIC INDUSTRY 81 

(lemonst rated tliat tlic cl.iy lias an averap:P tliickncss of 22 feet over 
four or five aeres. Sec sample No. isr», pa^e .'542. 

Bibl: State Mineralogist's lieport XXI, ]). 'M)2, July, 1925. 

W. A. Preston Property. "A bed of high-grade clay is found on the 
W. A. Preston holdings. Some of this has been used by R. II. Jenkins, 
of the Humboldt State Teaehers College at Areata, in the production 
of i)ottery and for experimental purposes."^ 

The Preston holdings (W. A. Preston, Box 387, Areata) comprise 
KiO aeres of i)atented land, the NE] of Sec. 2S, T. 6 N., K 1 E., H. M., 
adjoining the townsite of Areata. Mr. Jenkins reports- that the 
deposit is not of sufficiently good quality to warrant exploitation at the 
present time. 

Strong's Station. Mr. Malcolm B. Kildale, geologist, submitted a 
sample of bluish-gray plastic clay from near Strong's Station, on the 
Van Duzen River. This wa.s tested under samjJe No. 211. See page 
342. The deposit is stated to be extensive, but it is too far from the 
market to be of value, as it is only suitable for the manufacture of 
common brick. 

Sunny Avenue (Eureka) Deposit. On Sunny Avenue, one block 
south of Myrtle Avenue, in north Eureka, is an exposure of gray plastic 
clay that is typical of the sedimentary deposits of the vicinity. The 
exposure of clay that was sam])led is two feet thick, lying beneath a 
thin covering of sandy soil. The full thickness of the clay bed could 
not be determined from the exposures, but it is reasonable to expect 
a minimum of ten feet over an area of several acres, and it is likely 
that commercial deposits of similar material could be found in many 
]Jaces near Eureka or Areata, if needed. The clay is suitable for the 
manufacture of red brick and building tile, as shown by the test results, 
sample No. 183, page 326. 

Thompson Bricl" Company. J. D. Thompson, president and owner, 
]\Iyrtle and Harrison streets, Eureka. This company was formerly 
known as the Eureka Brick and Tile Co. The property is on Eureka 
Slough, 1.5 miles from Eureka, and covers 6.18 acres. There is a 
wharf at the plant. Coinmon brick, drain tile and hollow building 
tile are made from surface clay that occurs on the property. The drain 
tile is made in sizes from 3-in. to 12-in. diameter. 

The clay is mined from an open pit with a Fordson tractor and a 
Fresno scraper. The pit has a maximum depth of 12 ft., but good clay 
is known to extend to greater depths. The clay bed is made up of 
irregular streaks of yellow, gray and black clay, with a varying pro- 
portion of sand. It is generally too plastic to be successfully used 
alone, and is mixed in the plant with a maximum of 15% of sand. The 
clay is dumped from the scraper into a hopper and from there it is 
elevated to the head of the plant in cars drawn by a cable hoist. 
Sample No. 182 was taken from the deposit. See page 326. 

In the plant, the clay is passed through a disintegrator, followed by 
a pug-mill and a Brevan auger machine equipped with a wire-cutter. 
The brick or tile are air-dried under sheds. In the cool, moist atmos- 

•State Mineralogi.st's Report XXI, p. .^02, 1925. 
= Private communication, Aueu.st, 1026. 
6—54979 



82 



DIVISION OF MIXES AND MINING 



phere of the locality, drying? often requires a period of four weeks, and 
is seldom completed in less than two weeks. 

Firiiio- is done in a 30-ft. round down-draft kiln, wliich has a capacity 
of 7'), ()()() brick or the etpiivalent volnme of tile. Tlie water smokin<>' 
is done with wood, for a period of To honrs. The burn is finished Avitli 
oil, atomized with steam, reqniring 75 hours additional. The finishing- 
temperature is 1850° F. 

The machinery is operated by steam ])ower. generated in oil-fired 
boilers. From five to eight men are employed during the season. The 
capacity of the plant is 1,000,000 brick or its equivalent per year, and 
the output is usually about half that amount. The selling price of 
brick, f.o.b. \ard. is $20 to $22 per thousand. I'lioto Xo. 14 is a view 
of the plant. 

Bibl: State Mineralogist's Report XXI, p. 301, 1925; Prel. Kept. 
No 7. p. 46, 1920. 




Photo Xo. 14. Plant (^f Thomp.son Brick Co., Eureka, Cal. 
(Photo by C. McK. Liaizure, State Mineralogist's Kept. XXI, p. 301.) 



Weatherhy Ranch Deposit. "There is a deposit of clay of unknown 
extent on property of the Hanify Lumber Company, four miles south 
of Elk River, under lease to Clarence Weatherhy, Eel River, via Eureka. 
The strata exposed in a cut on a ridge through the property show clay 
underlain with two feet of fine volcanic ash. Underneath the ash is 
six feet of yellow clay, then two feet of lignite coal, with clay again 
below the coal. Some production of volcanic ash has been made, but 
the coal and clay liave not been developed. The Hanify Lumber 
Company's railroad runs within { mile of the deposit."^ 

' state Mineralogist's Report XXI, p. 302, 1925. 



CIjAY resources and CERAl^riC INDI^STRY 83 

IMPERIAL COUNTY. 
( Hy W. liiiti.iXf; TrcKKK, .Milling; lOiiKincrr.) ' 

General Features. 

The priiieii)al industries of Imperial County are agriculture, stock 
raising' and dairying. its mineral resources are vai'ied and extensive 
and the rajjid and continued growtli of the towns of Im})erial Valley 
and the manufacturing industries of tlie Pacific coast have h»d to the 
(U'velopment of deposits of slnicliiral and industrial materials llii-ough- 
out the county. 

Jm{)erial County is bounded on the east by the state of Arizona, noi'th 
by Riverside County, west by San Diego County and south by ]\Iexico. 
Its area is 4089 square miles, with a po])ulation of 43,388 (1920 census). 
The county is served by two railroads, the Southern Pacific and the 
San Diego and Ai-izona, each of which has several branches to 
important points. Two main paved highways afford easy access to the 
county from the north. The highway between San Diego and El Centro 
forms ])art of the coast route from Tjos Angeles to Imperial Valley, 
Yuma and Phoenix. The other route from Los Angeles is over the 
Valley Boulevard by way of Beaumont and Banning to Brawley and 
El Centro. The Blythe-Glamis route to Yuma and Imperial Valley is 
one of the main desei-t roads, which enters the county from the north- 
east at Palo Verde and runs southwest to Glamis, from which point the 
road follows the railroad north to Niland. 

Physiography. 

The most important feature of Imperial County is the broad and 
nearly level expanse of the Colorado River delta, which separates the 
Gulf of California from the Salton Basin and is known as Imperial 
Valley. The Salton Sea region is one of the interesting topogra])hicnl 
features of the county. Diagonally across the region, from southeast 
to northwest, it extends as a great trough whose lowest ])oint is nearly 
300 feet below sea level. On the west side of this deep trough rise the 
Peninsular Mountains, whose culminating points are 1 0,000 feet above 
sea level. On the east side is a desert containing irreguhir ranges and 
undrained basins ranging in altitude from a few hundred feet to 5000 
feet or more. 

The eastern border of the territory is formed by the Colorado River, 
whose waters flow through a low valley and Anally spread out over a 
huge delta as they enter the Gulf of California. 

The surface of the central portion of the Salton Basin is very even 
and nearly flat ; about its borders are alluvial slopes. In a number of 
l)laces rocky masses protrude above the even surface of the basin as 
rocky islands project out of the sea. Such island-like features are 
formed by Borego, Superstition and Carrizo mountains, the Cargo 
]\Iuchacho iMountains, Pilot Knob and a number of volcanic buttes 100 
to 200 feet high south of Salton Sea. 

The Sand Hills constitute an important feature of the physiography 
of Salton Basin. The sand hills east of Imperial Valley constitute the 
largest belt of dunes in this region and also one of the largest in the 
United States. They extend southeastward from the vicitity of Amos 

' state Mineralogist's Report XXII, pp. 248-285, 1926. Such portions of this 
report were used, with a few sHght alterations, as have a bearing on the clay 
resources of the county. 



84 DIVISION OF MINES AND MINING 

and ttM-iuinate a few miles beyond tlie ^lexican boundary, beinji,' about 
40 miles in len<itli and fi'om two to six miles in width. The crests of 
some of the dunes rise in places 200 to 800 feet above the hind on either 
side. 

Another interest in<i- I'ealiire of the Salton Basin is the old beach line 
which lies 40 to 50 feet above sea level and encircles Imperial Valley, 
the Salton Sea and part of Coachella Valley south of Indio. 

Geology. 

The most useful references on the geology of the region are Blake's 
original description of the Salton Basin/ and jNIendenhall's papers on 
Coachella Valley and Carrizo Creek,- Fairbanks' report,' and U. S. 
Geol. Survey Water Supply Paper No. 497, 'The Salton Sea Region, 
California, ' by John S. Brown. In the following notes on the geology 
of Imperial County excerpts are taken from the last-named paper : 

According to most geologists who have worked in this region, the 
oldest rocks are probably of pre-Cambrian age. The pre-Cambrian 
rocks occur mainly in the desert mountains in the region between the 
Salton Basin and the Colorado River. They are commonly flanked by 
Tertiary or later sediments about the mountain borders and in large 
areas they are covered or intruded b}'^ Tertiary volcanic rocks. The 
rocks that can most certainly be referred to as the oldest series consist 
of granite and granitic gneiss. In this series probably belong the 
granite and schist that compose most of the Cargo Muchaco Range and 
the granite, slate, and schist that form the basements of the Picacho 
Hills and the eastern part of the Chocolate Mountains. On the western 
border of the desert in Carrizo Mountain, and on the top of Fish ]\Ioun- 
tain in the Carrizo Creek region, are beds of marble and some schist 
and sandstone which have been referred by Mendenhall and Fairbanks 
to the Paleozoic, with suggestion that they may be Carboniferous. 
]\Iarble schist and gneiss of undetermined age in the Santa Rosa iMoun- 
tains may belong to the same series of rocks as the Carrizo Mountain 
district. 

Tertiary Sedimentary Deposits. 

Sedimentary beds, believed to be of Tertiary age, occupy extensive 
areas along the southwest and northeast sides of the Salton Basin and 
presumably underlie practically the entire basin. The largest and best- 
known exposures southwest of Salton Sea are in Carrizo Creek Valley, 
around Yuba Well, south of the Santa Rosa Mountains and northeast 
of Superstition Mountain and Borego Mountain, and on the north side 
of Fish Mountain. The Tertiary beds consist of soft, poorly consoli- 
dated conglomerates, sand and clay containing in places a large amount 
of gypsum and some other saline materials. Part of the Tertiary beds 
in the region are marine and part terrestrial. 

Tertiary and Quaternary Volcanic Rocks. 

The volcanic rocks of this area are probably' mostly Tertiarj^ ; some 
of them are Quaternary. They occur as flows interbedded with sedi- 
mentary beds in the Carrizo region, around Superstition ]\Iountain, and 
in Iris Pass. The lavas are most prorhinent in the Chocolate and Palo 

> Blake, TV. P., Pacific Railroad Reports, Vol. V. 1853. 

= Mendenhall, W. C, Ground waters of the Indio Region, Calif., with a sketch of 
the Colorado Desert: U. S. Geol. Surv.. Water Supply Paper No. 225, 1909. 

' Fairbanks, Harold W.. Geologv of San Diego, Orange and San Bernardino Coun- 
ties: State Mineralogist's Report XI, pp. 76-120, 1892. 



CLAY RESOURCES AND CEKA:MIC IXUUSTKY 85 

Verde mountains. The Palo Verde Mountains are entirely volcanic, 
bein<r chiefly a nuiss of andesitic or rhyolitic flows. The Chocolate 
Mountains, from one end to the other, exhibit a great mixtui-e of ande- 
sitic and rhyolitic flows with possibly syenite and trachyte in the 
west end. 

The only volcanic material of un(iuestionably Quaternary ap:e in this 
re*rion is found in the vicinity of the mud volcanoes southeast of Salton 
Sea, where three or four small buttes of black obsidian protrude through 
the Quaternary silt. 

Quaternary Deposits. 

The Quaternary deposits immediately underlie nearly all the low- 
lands and have the largest areal extent of all the rock formations. 
They underlie the larger ])art of the Salton Basin and practicall.y all 
of the Colorado River Valley. The valley fill consists of sand, gravel 
and clay washed down from the hills and mountains. 

Mineral Resources. 

Imperial County ranks as the forty-sixth county in the state's 
miiu'ral ])roduction. It contains de])osits of clay, copper, cyanite, gold, 
gems, gypsum, lead, manganese, marble, mineral i)aint, pumice, salt, 
silver, sodium, strontium, sulphur and talc, largely undeveloped. 

Clay Resources. 

Imperial County contains extensive deposits of river silt that has 
been used for the manufacture of common brick and tile. 

Extensive exposures of Tertiary clays are found on the west margin 
of Im])erial Valley toAvard Carrizo Creek. These clays are many miles 
in extent and of great thickness, but have not been prospected suffi- 
ciently to determine their value for commercial pur])oses. On these 
Tertiary clay deposits a number of locations have been made by the 
Columbia Cement Company, of Los Angeles, and the American Port- 
land Cement Company, of San Diego. Of special interest to the 
ceramic industry is the extensive deposit of cyanite at Ogilby. 

During the develo])inent of the towns of Imperial Valley, a numbei- 
of local brickyards have been established and operated for a short time. 
The Simons Brick Company, described below, is the only operator in 
the county at present. 

Full Moon Clay Deposit. The deposit is located on the southwestern 
slope of the Chocolate range of mountains, in T. 10 S., R. 16 E., S. B. 
B. and M., eight miles north of Iris siding on the Southern Pacific 
Railroad. 

Holdings comprise five claims known as the Full Moon group. Owner, 
J. Thebo, of La Mesa, California. 

The clay is a white talcose clay, showing a high alumnia content. 
The development consists of a number of o])en cuts along the surface 
outcrop. Analysis of clay made by A. J. Forget, of Los Angeles: 

Silica (SiO,) 27.93% 

Alumina (A1.,0.,) 42.33% 

Iron (FeoOa) 1-92% 

Lime (CaO) 0.53% 

Soda 0.70% 

Water (combined) 12.44% 

Moisture 0.74% 

Sulphur anhydride (SOa) 13.39% 

100.00% 



86 



DIVISION OF MINES AND MINING 



Simons Brick Companij. Walter R. Simons, president. Main office, 
125 West Third Street, Los Angeles. This company is the only manu- 
facturer of brick and tile in the valley at the present writing and only 
operates the plant at intervals to supph^ the local demand. The brick 
plant is located about one mile southeast of El Centro. 

The clay used is local silt of the valley, which is very fine and sticky. 
This dei)osit continues unchanged to a depth of 1500 feet as shown by 
local borings, but varies slightly in texture and the proportion of sand 
present, the variations in composition occurring every three or four 
feet. This variation enables the brick maker to mingle layers of differ- 
ent (puililies and form a brick mixture of suitable character. 

Tlie material from the clay pit is delivered by scrapers to the hop})er, 
from which it goes to a belt conveyor, and is elevated to a set of rolls. 
The material from rolls is elevated by bucket elevator to a screen. The 
through size from the screen goes to two stitf-mud brick machines. The 
brick and tile g(» to di'ving sheds, then are oil fired in open-field kilns. 




Photo No. 15. Vitrclrax cyanitc deposit. Cargo Muchacho Range, near Ugilby, 
Imperial County. Photo liy W. B. Tuoker ; Stale Mineralogist Rep. XXII, p. 270. 

Cyaxite and Dumortierite. 

C\vaiiite (Al,(),.SiO,) and dumortierite (8AU03.B,0,.6SiO,.n,0) 
are both aluminum silicates but with slightly different physical charac- 
teristics. Cyanite is an aluminum .silicate of the same chemical com- 
])osition as andalusite and sillimanite. but crystallizing in the triclinic 
system ; occurs usually in long-bladed crystals rarely terminated ; hard- 
ness, 5-7.25 ; gravity, 3.56-3.67 ; color, blue. 

An extensive deposit of cyanite occurs near Ogilby, which is being 
develo])ed by the Yitrefrax Comiiany. of TiOs Angeles. 

Dumortierite is a basic silicate of aluminum, witli boron, but crystal- 
lizing in the orthorhombic system. It occurs usually in small prisms; 
color, blue, dark blue and violet-red; hardness, 7; gravitx . 3.22-3.45. 

Dark blue boulders of dumortierite have been found in the Avashes 
in the Pieaeho district about 25 miles from Ogilby. These mt!tamori)hie 
minerals are found in the schists and gneisses. 



CLAY RESOURCES AND CERA:MIC IXDUSTRY 87 

0()ilb\j Cyanite Deposits. The de{)o.sits of eyaiiite occur near the 
base of hills on the western slope of the Cargo Muchaeho range of 
inonntains. three miles northeast of Ouilby. Elevation 500 feet. Hold- 
ings eoiiiprise ten claims known as the Drifted Snow and Blue Bird 
groups. 200 acres. Owner, Vitrefrax Company, 5100 Pacific Boule- 
vard, Los Angeles. 

The tii'st diseovery of cyanite was uuule in a low. rounded hill one- 
eighth mile wide by one-half mile long, and jjrobably consists of 25 per 
cent cyanite in a matrix of quartz. One-quarter of a mile farther east, 
a ])rominent vein of cyanite outcrops for one-half mile in length, at 
the foot of the Cargo ^Muchaeho I'ange. The vein, which occurs in a 
mica schist, is nearly vertical and varies from 10 to 200 feet in width. 
Open cuts and tunnels have been made along the deposit for a distance 
of over 500 feet along the strike. The most extensive showing has 
been found on the north end of the deposit. Here it outcrops for over 
200 feet in width. Quartz is the gangue mineral, while small amounts 
of black tourmaline occur throughout the vein material. On the south 
end of the deposit, both walls of the vein have a selvage of talc. 

Eight to ten men are employed in getting out material for shi])ment 
to the company's plant at Los Angeles, where it is being used in the 
manufacture of high-grade refractories. 

INYO COUNTY. 

(.V.y \V. BUKI.IXG TUCKKll.)' 

General Features. 

Inyo County lies on the eastern border of the state, north of San 
Bernardino County. It is the second lai'gest county in the state, with 
an area of 10,019 square miles. The population is but 7031 (1920 
census). Within the borders of the county are both the highest point 
and the lowest ])oint in the United States. IMount Whitney has an 
elevation of 14,501 feet, and Salt Flat, in Death Valley, is" 280 feet 
below sea level. 

In recent years the county has become more accessible with the con- 
struction of several automobile highways which supplement the railway 
lines that already served important i)oints. 

Geology. 

The general geology of the county has been described in detail in 
Report XV of the State Mineralogist, pp. 45 to 60, and a geologic ma]) 
accompanies that report. Granitic rocks form the backbone of the 
l)rincipal mountain ranges. Paleozoic and Mesozoic metamorphic 
formations, ])rineipally crystalline limestones, (juartzites, and schists 
are prominent in the eastern ])art of the county. These have been 
intruded by porphyry and diorite, and there have been numerous flows 
of rh\olite, andesite, and basalt. Tertiary sediments were deposited in 
the Death Valley region, and saline deposits formiMl from the evapora- 
tion of sea waters. 

In the higher mountainous sections are found many vein-forming 
minei-als, and in the lake beds of Death Valley saline deposits exist. 
The mineral resources include andalusitc, antimony, asbestos, bai-ytes, 

1 Inyo County, State Mineralogist's Report XXII, pp. 45.3-530, 192G. I'ortions of 
this article were abstracted for use in the present report. 



88 DIVISION OP MINES AND MINING 

borates, copper, dolomite, yeins, gypsuin, lead, marble, uiontmorilloiiite 
('bentonite,' 'shoshonite' and 'amargosite'), soda, sulphur, talc, 
tungsten, and zinc. The i)rincipal products are lead, soda, borates, 
bentonite, and silver. 

Clay Resources. 

Extensive beds of Tertiary clay occur along the Amargosa River in 
the vicinity of Shoshone and Tecopa. These beds vary in thickness 
from 6 to 20 feet and in different localities are covered with an over- 
burden of volcanic ash and gravel wash. 

Fairbanks Clay Deposit. R. J. Fairbanks, owner, Shoshone.. The 
property is situated one mile southeast of Shoshone, on the west side 
of the Amargosa River. The holdings comprise 160 acres. Elevation 
1600 feet. 

The beds of clay trend north and south and are 6 to 8 feet thick, over- 
lain by 4 to 6 feet of volcanic ash. The clay is green in color and quite 
plastic. 

The Pacific Minerals and Chemical Company and Gladding, McBean 
and Company, of San Francisco and Los Angeles, also own deposits of 
clay located between Shoshone and Zabriskie. 

KERN COUNTY. 
General Features.' 

Kern is the southernmost county in the San Joaquin Valley, and 
takes in the southern portion of the Sierra Nevada ^Mountains, includes 
a portion of the Coast Range in its western end, and to the south and 
east of the Sierras it encloses a large section of the ]\Iojave Desert. The 
total area of the county is 8100 square miles. It is the third largest 
county in the state, and is bounded on the north by Tulare, Kings and 
Inyo, on the south by Los Angeles and Ventura, on the east by San 
Bernardino, and on the w^est by San Luis Obispo. It is characterized 
by greater variety and contrasts of topography, geology, climate, and 
resources than any other California county. 

The northern i)art of the county is well provided witli water and 
power for industrial, agricultural and mining purposes. In the south- 
ern part of the county, on the ]\Iojave Desert, water is relatively scarce, 
but power can be secured for all important purposes from the lines of 
the Southern California Edison Company, now one of the largest power 
systems in the world. Transportation facilities are provided to import- 
ant points in the county by the Southern Pacific and Santa Fe railroads, 
supplemented by a system of state and county highways. 

The principal mineral product is petroleum, the production of wliieh 
maintained for many years the supremacy of Kern County among all 
counties of California in the value of its mineral output. Kern was 
surpassed by both Los Angeles and Orange counties in 1923, but by 
Los Angeles only since then, for which petroleum also is responsible. 

Among the commercial mineral products of the county, in addition 
to petroleum, are natural gas, borates, cement, brick and clay, gold and 
silver, salt, miscellaneous stone, and antimoii.w Other minerals that 
have been discovered or that have been worked in the i)ast are: as])lialt, 

'State Mineralog-ist's Report XIV, itp. 471-475, lOH. 



("LAY RESOURCES AND CERAMIC INDUSTRY 89 

coppei-, fuller's eartli, p:ems, yypsum, iron, Ic.ul. limestone, magnesite, 
marble, mineral paint, potash, soapstone, soda, siili)hiir, and tungsten. 

Clay Resources. 

The alluvial silt of the San Joaquin Valley, in the vicinity of Bakers- 
field, has been in use for many years for tlie manufacture of common 
brick. As is the case in Fresno County, deposits of plastic common 
clay are scarce. The local silts have barely enough plasticity to permit 
the manufacture of a satisfactory grade of common brick by the soft- 
mud process. Two brick plants are in operation in Bakersfield. 

A deposit of high-grade clay at Kosainond, near Mojave, has attracted 
attention for many years. It is possible that more extensive prospect- 
ing in the desert region Avill disclose other deposits of high-grade clays. 

Bakersfield Rock and Gravel Companu. A. II. Kaspe and W. J. 
Walters. It is reported ^ that this company was developing clay lands 
in 1927, in coniiection with its saml and gravel business. A conveyor 
system, storage bins, and loading equi]>ment were to be installed, at a 
cost of $18,000. Further details are lacking at the time of going to 
press. 

Balicrsfidd Sandstone Brick Compayiy. James Curran, manager. 
Office and plant at 501 Sonora Street, Bakersfield. The company owns 
40 acres of land. 

Common red brick are manufactured from an alluvial silt which is 
mined to a depth of ten to twelve feet Avith a clam-shell excavator. 
The soft-mud process is used. The plant is equipped with a pug-mill 
and a Martin press. Drying is done on steel trucks, either in the open, 
or under sheds. As the plant is only operated during the dry season, 
drying is usually completed in seven days. Firing is done in field 
kilns, whieli are started with gas and finished with oil, atomized with 
steam. Thermo-electric pyrometers are used for recording tempera- 
tures. At the fire-holes, the finishing femj)erature is 2100° F., two 
feet above the arch it is 1840° F., and two feet below the top it is 
1750° F. 

The eajiacity of the i)lant is 40,000 brick a day, and 14 men are 
(■iu])l()yed dui'ing the operating season. 

Bibl : State Mineralogist's Kept. XIV, p. 477; and Prel. Kept. No. 

7, p. 48. 

Kern County Brick Co. Owned by King Lumber Co., Elmer King, 
l)resident, Bakersfield. This property comprises 12 acres in Sec. 21, 
T. 29 S., R. 28 E., M. D. M., on the eastern outskirts of Bakersfield. 
The deposit is a sandy loam 25 feet thick, and has been used for the 
])roduction of common brick since about 1900. The soft mud process 
is used, the equipment consisting of a disintegrator, pug-mill, and 
6 mold press. Cable haulage is used to transjiort the brick from the 
l)resses to the drying sheds. Firing is done in oil-fired field kilns. 
The capacity of tlie plant is 37,000 brick per day, the annual produc- 
tion depending upon local demand. Ten men are employed. 

Titus Chn/ Deposit. H. E. Titus of Kosamond owns two ])lacer 
claims totaling 40 acres, comjirising the K\W \ of the SE] of See. 11, 
T. 9 N., R. 1-') W., S. B. M., covering a deposit of pottery clay of good 

■ Clay-Workor, May, 1927, p. 486. 



90 DIVISION OF MINES AND MINING 

quality. Tlie (listaiice by road i'l'oiu Ivosaiuond is 4.8 miles in a direc- 
tion slightly north of due Avest. The clay has been developed by an 
open pit, and by a 200-foot tunnel, noAv inaccessible. 

The clay is enclosed in felsite porphyry, and is apparently a local 
alteration and docoiiii)Osition in ])lace, of a phase of this rock. Inclu- 
sions of porphyry in various stages of alteration are intermingled 
with the clay. The deposit has no definite stratification, but appears 
to lie in a nearly Hal bed, overlain by a red-c<)h)i'ed porphyry capping. 

Tlie known dimensions of the deposit is 800 feet wide, 700 feet long, 
and 50 feet dee]i, with unknown possibilities for extension in any of 
these dimensions. The ])roperty was formerly known as the Hamilton 
deposit. At various times during a period of over 10 years, clay has 
been mined from an o]ien pit, and shi])ped to ceramic plants in the 
Los Angeles district, notably the Los Angeles Pottery Company and 
the Pacific Sewer Pipe Company both of whicli are now non-existent 
under their original names or ownership, and more recently to the 
Tropico plant of Gladding, ^McRean & Co. Tlie clay has been used in 
stoneware and sewer-pijie mixtures, and a commercial test run has been 
made for terra cotta mixtures. It is likely that the property will 
eventually be acquired by one of the manufacturing companies, although 
at present develojuuent work has not progressed far enough to permit 
a prediction as to the probable tonnage and quality that can be expected 
beyond the known limits of present knowledge. Sample Xo. 114 was 
taken from this dei)osit, and the test results are given on page 312. 

IT'. ^'. Wehh of Rosamond owns a ])roperty one mile west of the 
Titus claims, on what is a supposed extension of the same clay bed. 
This property was not visited. 

Merry Widow Mine. Mrs. ]Mary Y. Smith of Kosamond is the prin- 
cipal owner of the ]\Ierrv Widow mine comprising two lode claims in 
the SWi of Sec. 8, T. 9 5j., R. 12 W., S. B. M., 2.8 miles by road north 
of Rosamond, of which 1.6 miles is on the highway to ]\Iojave. This is 
in the Rosamond gold mining district, uoav idle, but at one time a small 
jiroducer of gold from narrow veins in granite porphyry and slate. 
Two samples were taken from an 800-foot tunnel on the ]\Ierry Widow 
property. One of these, No. 115, is footwall gouge from a drift on a 
vein encountered at a point 200 feet from the portal of the tunnel. 
The gouge is over five feet in thickness, and lies at an angle of 45 to 50°, 
dipping south. About 40 feet of this material, measured along the 
strike of the vein, is exposed in the drift. The test results, page 349. 
slioAV that the clay has little value for ceramic purposes, on account of 
jioor plasticity, red color, high shrinkage, fire splitting, and low fusion 
point. 

The other sami)l(', Xo. 116, was taken of the decomposed rock that 
occurs near the portal of the tunnel. It is evidently an altered granite 
porphyry. Test results, ])age 349, were even less favorable than those 
obtained on sample Xo. 115. 

KINGS COUNTY. 
General Features. 

Kings County is in the south-central portion of the state, soutli of 
Fresno County. Its ai'ea is 1559 sfpuire miles, and tlie po])ulation is 
22,031 (1920 census). The principal town is Ilanford. The western 



CLAY RESOURCES AND CERAMIC INDUSTRY 01 

edjfe of the county is in the foothills of the Coast Range. The rest of 
the county is in the basin of the San Joaquin Valley. 

The mineral resources of tlie county are jiractically undeveloped. 
Dejiosits of fuller's earth, gypsum, mineral paint, natui'al gas, and 
([uit-ksilver have been noted. The commercial production is almost 
negligible. 

Clay Resources. 

Common brick clays are rcasonabl\' abuudaut in llic vicinity of Han- 
ford and elsewhere in the county. Two former brickyards, the Clinker 
Brick Company and Trewhitt Brickyard, both near Ilanford, were 
abandoned prior to 1911. 

Bibl: State .Alineralouist's Kept. XIV. p. 527, 1913-14; State :\Iin. 
Bur. Bull. ;J8, p. 24:3 ; Prel. Kept. 7, ]). 49. 



LAKE COUNTY. 
General Features. 

Lake is one of the counties north of San Francisco Bay. It is 
bounded on the north by ^Meiidoeino aiul (Tlenn counties, on the east by 
Glenn, Colusa and Yolo, on the south by Napa, and on the west by 
Sonoma and Mendocino. It has an area of 1328 square miles, and its 
])oj)ulation is 5542 (1920 census). 

The outstanding physiogra])hic feature of tlie county is Clear Lake, 
which has been a prominent resort area for many years. Clear Lake is 
surrounded by rolling hills in which are many interesting geological 
features. The prevailing rocks in the county are the Franciscan 
(Jurassic) serpentines and slates and Tertiary volcanics. There is a 
small area of Pliocene, and an area of Quaternary near Clear Lake, 
besides some undifferentiated Tertiary formations at the southern 
extremity of Clear Lake.^ 

^Mineral ]n-oduction in the i)ast has beeji comjiai'atively small, and has 
been largely confined to quicksilver and mineral water. Some of the 
leading minerals found in this section, in part as yet undevelo])ed, are 
borax, clay, copper, gems, gold, gypsum, mineral water, quicksilver, 
silver, and sulphur. 

The entire county is but sparsely settled, and is without rail connec- 
tions. Besides the production of minerals, the population is engaged 
in farming, stock raising, and the operation of summer resorts at the 
numerous mineral springs in tlie county, and on the shores of Clear 
Lake. 

Clay Resources. 

The county was visited by the author in September, 1925, and 
attempts were made to examine clay occurrences that had been repoi'ted 
previously by the Bureau,- in which had been mentioned a line of 
kaolin deposits near the Mount Sam Quicksilver Mine, and undeveloped 
deposits at Glenbrook, Kelseyville, Soda Bay, and Sul])hur Bank. 
Tmpiiry was made among local inhabitants, and a number of localities 
were visited, but no evidence of tiicsc dei)osits could be discovered. As 

1 Smith. .T. P.. The geologic formation.s of California: Gal. State Min. Bur. Bull. 
72. and geologic map. 

= Bull. 38, IX 361. Rept. IX, p. 303 ; XIV, 204. Prel. Kept. 7, p. 49. 



92 



DIVISION OP MINES AND MINING 



time was not available for prospecting, the search was abandoned. It 
is obvious that only a deposit of exceptionally high-yrade clay would 
have commercial value in this region, on account of the cost of trans- 
portation to market, and while the possibility that such a deposit may 
be found can not be entirely eliminated, it is unlikely. 

Common brick clay is not abundant in this region, but there is little 
likelihood that a brick yard will ever be established on account of lack 
of market. A few samples of common clays were taken from deposits 
near Kelseyville, but only one of these, No. 188, was tested. This is 
a clay shale from an undeveloped exposure 1.4 miles southeast of 
Kelseyville on the Lower Lake road. The test results are on page 336. 



General Features. 



LASSEN COUNTY. 



Lassen County is in the northeast portion of the state, south of 
Modoc, which is the northeasternmost county. Its area is 4531 square 
miles, and the po])ulation is 8507 (1920 census). It is a succession of 
mountain ranges and high-altitude plateaus, and is only partly devel- 
oped. Almost the entire area of the county is covered with Tertiary 
and Quaternary lavas. In the vallej's and around the shores of lakes 
are Quaternary sediments. Occurrences of cop])er, gems, gypsum, 
gold, silver, and sulphur are known. There is a small annual produc- 
tion of gold, silver and miscellaneous stone. 

Clay Resources. 

The county was not visited in the course of the ])resent investigation. 
It is obvious that only clays having exceptional unit value could be 
commercially produced in the region. A deposit of clay is reported on 
the Anderson Kanch, at Hayden Hill, owned by H. P. Anderson, but 
details are lacking. Hayden Hill is a gold mining district. It is pos- 
sible that kaolinization of some of the rhyolite tuffs, especially those 
high in alumina, that are known to occur in this district, may have 
resulted in the development of high-grade clays. 

In Preliminary Report 7, ]). 49 (1920), the following notes are given: 

"J. E. Pardee, Susanville. Common brick clay. No recent pro- 
duction. 

"A. E. P>uchler, Susanville. Formerly operated a clay deposit, but 
no recent production." 

No recent data are available. 



LOS ANGELES COUNTY.' 
General Features. 

Los Angeles County is bounded on the north by Kern County, on 
the east by San Bernardino County, on the south by Orange County, 
and on the west by Ventura County and the Pacific Ocean. 

The ocean shore line extends for about ninety miles. The county 
comprises 4067 square miles, a large part of which is mountainous. 
The population, according to the 1920 census, is 936,438. 

The chief topographic features of the county are the mountain 
ranges, the valle\s, and the great Los Angeles Plain which stretches 



1 Tiu-ker. W. B.. I^os Aiife'elt-s County. Slati- Mineralngi.'^f.s Report XXIII. p. 287. 
et sen. No data on the ceramic industry are given in thi.s reference, but Mr. Tucker's 
general description of the county was freely drawn upon. 



CLAY RESOURCES AND CERAMIC INDUSTRY 93 

Iroiii the footliills t<i llic sen. The liiLiiicst jx'iiks of the nioiiiiljiins are 
ill the San (Jahriel i\aii<ic, in the iidit lieastern part ol' llie c-ounty, and 
arc over 10, ()()() I'eet liijili. Other iaiiji:es in the eounly ai"e the Santa 
Susana and Santa Monu-a. The San (lahiiel ilan.ue is ehielly formed 
of crystalline roeks, with its central axis eonsistinji: of granite, with 
gneisses and schists on its flanks. The Santa Susana and Santa Monica 
i-anges are chiefly formed of Tertiary setlimentary rocks. 

There is oidy a small i)r()diiction of metals in Los Angeles County, 
its principal iiiiiicial wealth being in struct ural and industrial materials, 
petroleum, and natural gas. Since 1923, Ijos Angeles County has led 
all other counties of the state in the value of its mineral j)r()duction, 
largely due to its i)etroleum jjroduetion. 

Among its mineral resources may be noted asi)halt, barytes, borax, 
brick, clay, eoi)i)cr, diatonnte, fuller's earth, gems, gold, gypsum, lead, 
limestone, marble, mineral j)aint, mineral water, natural gas, petroleum, 
glass sand, sandstone, serpentine, silver, soapstone, miscellaneous stone, 
and zinc. 

Clay Resources. 

Los Angeles county is especially fortunate in that there is an ample 
supi)ly of common clay and sliale for the manufacture of heavy 
structural ware, such as common brick, hollow tile, roofing tile, sewer 
pipe, etc. Close to the metropolitan area of the city of Los Angeles 
are numerous deposits of shale and loam that have been in use for 
many years for the manufacture of these products. Property values 
have increased to such an extent in recent years that many of these 
deposits have been sold for business or industrial purposes, but there 
are still a number of plants in operation within a radius of one mile 
from the business center of the city. In the outskirts of the city, on 
almost every side, Avithin a radius of 20 miles from the downtown sec- 
tion, are numerous clay and shale deposits that are being utilized by 
the ceramic iiidustry. Perhaps the most important of these deposits 
is in Santa Monica, where a number of brick yards have been estab- 
lished, and from which clay is mined for use in other plants of the 
county. The Santa ^Monica clay is not only suitable for the manufac- 
ture of common brick, but is extensively used in hollow tile, roofing 
tile, scwei- pipe, electric conduit, face brick, and other structural ware 
bodies. 

No high-grade clays are produced in the county. It is claimed that 
high-grade clays occur on the Malibu Ranch, north of Santa Monica 
(see under ]\Ialibu Pottery), but these have not been extensively ])ros- 
pected, and at this writing little information was available as to the 
extent and character of these clays. 

On account of extremely favorable industrial conditions in the Los 
Angeles district, with a combination of cheap power, fuel and labor, 
adequate spur track facilities, equable climate, and an extensive market 
arising from the rapid growth of the region, there are a large number 
of ceramic plants in the county, and practically every commercial type 
of ceramic ware is being manufactured in one or more plants. The 
high-grade clays needed by the industry are largely obtained from the 
Alberhill-Corona deposits in Riverside County and from deposits in 
Orange and San Diego counties. The freight rate on clays from the 
Alberhill district is about $0.90 per ton, in carload lots, and the costs 



94 DIVISION OF MIXES AND MINING 

of miniiiy are relatively low, so that most grades of clay from Alberhill 
can be delivered in Los Angeles at a cost of $2 to .^6 per ton. Some 
Lincoln and lone clays, from Placei- hiuI Aniadoi- counties, respectively, 
are shipped into Los Angeles for use in the manufacture of terra cotta. 
floor tile, stoneware, and ])()ttery. English china and ball clay, and 
clays from Florida and Kentucky are also imported for the manufac- 
ture of whiteware and tile, at a cost of $14 to $25 per ton, delivered. 
Southern California abounds in deposits of feldspar and silica, 
especially in San Diego and Riverside counties, so that these materials 
may be secured by the local industry at comparatively moderate cost. 

Descriptions of individual clay deposits and ceramic plants follow. 
The field work' was done during the summers of 1925 and 1926, and 
the industry has been growing and changing rapidly, so that it is 
obviously impossible to present the latest information on all plants. 
Attempts were made by correspondence to bring all material up to date 
as of November, 1927, but in many cases no replies had been received 
at this writing. Mr. Tucker, of the ^Mining Division, rendered valuable 
service in obtaining data on a number of plants in November and 
December, 1927. 

Acme Brick Compayixj} Thos. Kelley, president ; R. L. Worthington, 
secretary. Office and plant in Santa Monica. The company owns 20 
acres of land and manufactures common brick only. The dei)osit con- 
sists of 20 to 30 feet of red and yellow clay, overlain by two feet of soil. 
The clay is mined in an open pit by a gasoline shovel, which loads into 
3-ton side dump cars. The cars are hoisted up an incline to a hopper 
at the plant. 

The soft-mud process is used. The clay is ground in a dry pan, 
elevated by a bucket elevator to a ^-inch impact screen, ])ugged in two 
pug-mills in series, and finally i)asses to the brick ])ress. which has a 
capacity of 60,000 brick i)er day. The oversize from the .screen is 
returned to the dry pan for regrinding. 

Conveyors are used to transport the brick to and from the drier, 
which is heated by steam from two 150-h.]). oil-fired boilers. Drying is 
completed in from 24 to 36 hours. 

Six oil-fired field kilns are in use, having a capacity of 600,000 brick 
each. 

The plant operates thronghout the year. Forty men are employed, 
and 135 h.p. of electric power are installed. 

AJhamhra Kilns, Inc. E. H. Ockerman. Alhambra. The company 
now operates two plants, one at Alhambra and the other at Santa 
Monica. The site of the Alhambra plant was visited by the author 
shortly after construction was .started, in September, 1926. A request 
for recent information was addressed to the company on November 11, 
1927, but no reply had been received at this writing. It is known that 
hand-made roofing tile and patio floor tile are being made. 

American China Company. W. N. Reeves, oAvner, 2304 East Fifty- 
second Street, Los Angeles. This company specializes in single-burn, 
glazed tile, ready-set for soda fountains, fire places, etc. A portion of 
the tile used is* made at the plant from Alberhill clays, principally 
E-101 and SH-4 (samples No. 11, p. 257. and 273, p. 273), and also 

• Data supplied by W. B. Tucker, district mining engineer, December, 1927. 



CLAY RESOTMtCES AXD rERA:\ri(' TXHUSTRY 95 

some clay from the Emsco i)it near Corona. The balance of the tile is 
])ureliase(l from tlie (Vilifornia Clay Products ('oiui)any. 

The wai-c is huriicd for 2f lionrs in a jias-fii'ed Uilii liaviii<i' a ca])acity 
(tf 400 s(|iiare feet oi' tile. The output of tlie plant varies Avitli the 
demand up to 70,000 s(|. ft. per year. 

American Encmistic Tiling T'o., Ltd. Fraidv A. Philo, general man- 
ager, Crawford Massey and ]Mr. Schreiber, ceramists. Los Angeles 
idant at 2080 East Fifty-second Street ; Hermosa F.each ]dant at 700 
Fifteenth Street. Tlu^ Ijos Angeles i)lant -was built by the West Coast 
Tile Company and ]iurcliased in 1919 by the American Encaustic Tiling 
Co., Ltd., a nationally luiown manufacturer of ceramic floor, wall, and 
decorative faience tih\ witli jdauts at Zanesville, Ohio, and JNIaurer, 
X. J., and witli head ot^ces at 16 East Foi'ty-first Street, New York 
City. The Ilermosa Beach plant was purchased by the company from 
the Prouty-line Products Company in 1925. 

The company marl^ets a com])lete line of vitrified and semi-vitrified 
glazed and unglazed floor, wall, and decorative faience tile. Both the 
Los Angeles and Ilermosa Beach plants manufacture a large variety 
of colors in glazed, unglazed, and decorative tiles. 

With such a diversity of products, it is natural that the raw mate- 
rials in use at the plant cover a wide range. It has been found that in 
order to minimize plant difficulties, and to secure a uniformly high- 
grade product, it is necessary to use a good quality of English china 
clay, Florida kaolin, English and Kentucky ball clays, in practically 
all of the white or nearly-white burning mixtures, rather than to 
attempt to rely upon California materials. However, some of the clays 
used at the Los Angeles plant, and all of the clays used at the Ilermosa 
Beach plaiit, are obtained in the State of California. Quartz and 
feldspar are obtained maiidy from tlie large deposits owned by the 
company in Riverside County. The company also owns a deposit of 
'Cornish Stone' (Sample No. 58), at Dehesa, San Diego County, which 
is used as an ingredient of a hard, white, vitrified tile, known under 
tlie trade name of "Kaospar. " 

The Los Angeles i)lant covers about 3^ acres and the Hermosa Beach 
plant about 2| acres. Both ])lants are completely equipped, well 
arranged, and efficiently operated. At the Los Angeles plant all of 
the materials entering tlie ])lant are ground in mills suited to each 
material, and imrticular care is exercised to avoid contamination with 
iron. This necessitates the use of wood or porcelain liners in the 
pebble mills for grinding to ])ass 140-mesh screen. Imported Danish 
flint pebbles are used as local pebbles have proved to be lacking in 
hardness. After grinding, the mixtures are prepared by adding the 
])roper amount of each material to double blungers. The 'pulp' is 
then treated in filter presses, dried in gas-heated dryers to about 10% 
moisture, broken through 20-mesli screen, tempered with sufficient 
moisture to insure the proper consistency for dry pressing, and stored 
in bins until ready for use. 

Most of the tiles are formed by dry pressing, using either power- 
driven or hand-operated presses, depending upon the quantity of each 
size and color required as well as the shape of the tile. 

At the Los Angeles plant the bodies are fiired in 12 gas-heated bee- 
hive kilns, approximately 20 feet in diameter by 12 feet high. The 



96 DIVISION OF MINES AND MINING 

firing sclitHlule requires foiu- to five dnys lieatiiij;', and tliree to four 
daj's cooling, the maximum tem])eratnre corresponding to cone 11 
(1285° C). Ui)on the completion of this firing, the tiles that are to be 
glazed are transferred by truck to the glazing room -which is in a sepa- 
rate building a short distance from the biscuit kilns. After ap])h4ng 
the glaze mixture, the tiles are re-fired in a Harrop tunnel kiln which 
is approximately 250 feet long, 8 feet wide, and 8 feet high. The glost 
cycle occupies about 54 hours, reaching a maximum temperature corre- 
sponding to cone 01 (1110° (J.). At the Ilerniosa Beach plant both the 
biscuit ware and the glazed ware are fired in five specially-designed 
tunnel kilns, the firing temperature being about the same as that used 
at the Los Angeles plant. 

All temperatures are controlled by the use of a pyrometer, either of 
the intermittent or continuous recording type. 

Each plant is equipped with a machine shop for making all ordinary 
repairs, and for making the dies used in the presses. A complete 
experimental laboratory, equipped with ball mill, mixing pans, blunger, 
filter press, etc., in charge of an experienced ceramic engineer, is main- 
tained at each plant for the purpose of studying bodies and glazes, 
and to aid in the solution of operating difficulties. 

Both plants together employ ap])roximately 600 persons. 

All tiles sold by the American Encaustic Tiling Co., Ltd., are made 
by them in their own plants in the L^nited States of America. 

Bibl: State Min. Bur. Prel. Kept. No. 7, p. 62 (West Coast 
Tile Co.). 

American Refractories Company. F. E. Keeler, president; Earl 
McClintock, vice president ; G. Raj' Boggs, general manager and secre- 
tary-treasurer. OfBce and plant at 3232 Alosta Street, Los Angeles. 

This compam^ is engaged in the manufacture of fii'e brick for flue 
linings, kilns and boiler settings, and silica glass-tank blocks. One of 
the si)ecialties is the manufacture of radiant stove backs. 

The company controls the Hunter Ranch clay deposit in Orange 
County (samples 63 and 64), and purchases other clays from the Alber- 
hill district. 

The clays as received at the plant are stock piled, from which they 
are fed hy wheelbarrows in the proportions desired for the various 
mixes to an 8-ft. dry pan. The dry pan ])roduct is elevated to a 
screen, which delivers oversize to the dry pan for regrinding, and 
undersize to a double-shaft and a single-shaft pug-mill in series. From 
the pug-mills, the plastic mix is fed to an American auger machine. 
All machine-made brick are repressed in a Raymond press. Some 
grades of brick, particularly the 'Arc' brand, are made by hand 
molding, and all special shapes and glass-tank blocks are hand molded. 

After shaping, the ware is transferred on hand trucks to a waste- 
heat drying floor. Drying usually requires about three days. 

The radiant stove backs are made by dry pressing, and are fired in 
two down-draft rectangidar kilns, 7-f't. by 9-ft. and 6-ft. by 8-ft. in 
size. Brick and other shapes are fired in four 28-ft. round down-draft 
kilns. Natural gas is used for all firing. The round kilns are fired 
to cone 13 (1350° C.) in ten days and are cooled by the aid of exhaust 
fans in six days. Allowing five days for drawing and setting, the 
complete cycle requires 21 days. 



CLAY RESOURCES AND CERAMIC INDUSTRY f)7 

The capacity- of llir plant is ir),()()() sfaiulard !)-in. brick a da.w or its 
i'(piival('ii1 ill (ttlicr \\;ii('. Twonty-five iiicii ai'(> employed. 

Angulo Tile Cotnpanif. riant No. 2; R. F. Anfrulo and Sons, owners. 
Tliis company lias two plants en^a^cd in the mannfactui-e of hand-made 
Mission roof and terrace tile. Plant No. 2 is at Reseda, Los Anyeles 
County, and Plant Xo. 1 is in Santa Barbara (see nnder Santa I^>arbara 
County). The Reseda i^lant is llie larm'r operation. Clay is obtained 
from a surface de])osit adjoininji' the plant. A tile maeliine ha.s recently 
(November, 1927) been added to the ecpiipment. The company has a 
V. S. i)atent on a s])ecial method of making- hand-made rooting tile. 
The ])lant is eqnii)ped willi three kilns, fired with gas and oil. 

Atlas Fire Brick Comimmi. M. I. Power, president; C. J. Walters, 
vice i)resident ; Stuart Findley, secretary; Clifford Tillotson, manager. 
Office and plant at P>oyle and Slauson avenues, Los Angeles. 

This comi)any specializes in the manufacture of silica brick and high- 
grade fireclay brick. In addition to standard straight fire brick and 
silica-brick shapes, the company is prepared to make all key and arch 
shapes, glass-tank l)locks, and special shapes. 

The raw materials in use include the Emsco white pla.stic fireclay 
(sample No. 70, p. 272) from Riverside County, German fireclay (sam- 
ple No. 56, p. 297) and ganister from the coiii])any's deposit near Hicks, 
San Bernardino County. From 6000 to 12,000 'tons of clay and :5000 
to -lOOO tons of ganister are used each year. 

The mixtures are prepared by dry-pan grinding, followed by pugging. 
All ela,y brick mixtures are repugged, and then aged in a moist room for 
a period ai)i)roximating two weeks. The silica brick are all hand molded. 
Special care must be taken with the large glass-tank blocks, to ensure 
thorough tamping during molding. Fire brick are made by either the 
dry i)i-ess or wet process, the latter being by hand molding, followed by 
repressing. 

All shapes are air dried, then fired in gas-fired round down-draft 
kilns. Fire brick are fired to cone 12 (1310° C.) and to cone 14 
(1390° C.) ; glass-tank refractories to cone 12; and silica brick up to 
cone 18 (148o° C). Seven kilns are in operation, and 40 men are 
employed. 

Batchelder-Wilson Co. E. A. Batchelder and L. H. Wilson, owners. 
Office and plant at 2633 Artesian Street, Los Angeles. This company, 
formerly known as the Batchelder Tile Comjiany, specializes in decor- 
ative tile for homes, and their arti.stic products have become well-known 
throughout the region west of the Rocky JMountains. The ])rincipal 
products are facing and paving tile for interior decorating. Some 
architectural terra cotta is i)roduced for entrance ways and interiors. 
The clays used are Hill blue (samjjle No. 9, p. 287), extra select 
main tunnel (sample No. 18, p. 321) and some pink mottled (sample No. 
7, p. 328), supplied by the Alberhill Coal and Clay Company in River- 
side County ; Lincoln No. 1-6 (sample No. 146, p. 303), from the Lincoln 
Clay Products Company in Placer County; Bacon red (sample No. 
127, p. 335), and Harvey (sami)le No. 133, p. 298), from lone, Amador 
County, and a small quantity of Santa IMonica clay (represented by 
sample No. 61, p. 341). Some bentonite from a deposit near Araboy, San 
Bernardino County, is used in the nnderglazing slip. 

7—54979 



98 DIVISION OF MINES AND MINING 

Six standard mixtures are used, jTrading in fired-body color from red 
to cream. The mixtures are i)rei>ared by jaw erushiiiK, roller-mill .grind- 
ing, and final png-mill mixinf; and tempering. The batches are seasoned 
in moist rooms before pressing, a i)eriod of at least two weeks being 
preferred. 

All of the jn-oducts are hand moulded in plaster molds, which are 
made in the plant. The drying is in air, followed by automatic drying 
ovens. The total drying time is about 48 hours. After drying, an 
underglaze slip is sprayed on, followed by the color decorations, Avhich 
are ])ainted by hand. 

The kiln equipment includes two 7 x 12 foot rectangular kilns, 
two 20-foot round down-draft kilns, and one 200-foot tunnel kiln, all 
gas fired. A great variety of colors from the same body and glaze is 
produced by varying the temperature and atmospheric conditions dur- 
ing firing. Pyrometers and cones are used on all kilns for controlling 
temperatures. 

After firing, some of the tile are buffed on emery wheels to remove 
a part of the glaze. This is followed by several sprays of raw lin.seed 
oil, thus producing a pleasing mottled effect. 

Monorail transportation is used throughout the plant. 

A small testing laboratory, in charge of a ceramic graduate, is 
maintained. 

J. A. Bauer Pottery Co. W. E. Bachman, president, 415 West 
Avenue Thirty-three, Los Angeles. This is a four-kiln pottery making 
a complete line of red flower pots, white stoneware, yellow bowls, 
crocks, vases, and olla.s. Santa ]\Ionica clay (sam])le Xo. 61, p. 341) is 
used for flower pots and ollas, while Alberhill and Lincoln clays are 
used for the light-colored, vitrified stoneware bodies. Approximately 
4000 tons of clay are consumed per year. 

The clays are spray-washed to remove surface contamination, then 
pugged. Flower pots and some of the other ware are machine molded. 
For other products turning (' jiggering') or hand moulding are used. 
All of the smaller ware is dried in 24 hours, natural gas auxiliary 
heating being used in the drying room. White, yellow or cream glazes, 
where used, are applied by dipping before firing. A single firing 
matures both the body and the glaze. 

The four kilns are of the round down-draft type, fired with gas, but 
equipped to burn oil if necessary or desirable. The red ware is burned 
to a temperature of 1850° F. in three to four days, and the cream body 
ware is fired to 2250° F. in about the same time. One of the kilns is 
ordinarily operating on the light colored body, and is equipped witli 
pyrometric control. 

At present this is the only plant in Los Angeles manufacturing floAver 
pots. Not over half of the company's business is in flower pots, but 
this constitutes the largest single item. In order to permit the full 
time operation of the plant on a systematized plan, a stock of ware 
aggregating over $100,000 in value is constantly kept on hand. 

Fifty men are employed. 

Bibl : Cal. State Min. Bur. Prel. Kept. Xo. 7, p. 50. 
California Brick and Tile Company.^ (Formerly the Owens Brick 



Data supplied by W. B. Tucker, district mining engineer, December, 1927. 



CLAY RESOURCES AND CERAMIC TKDTTSTRY 99 

Company.) K. A. Miller. ])resi(l(iit ; 11. W. Urou^hton, secretary. 
Office and i)iant at (}1.')9 Kcstcr Street, Van Nuys. The company owns 
*J(t aeres of land, and mannl'actni'es cojnnion bi-ick only. 

TIk' de[)osit consists of red and yellow clay, 20 to .']() feet tliick, 
nnderlyinji: an overhnrden of soil Jroni one to two I'eet tliick. The 
clay is excavated from an open pit by a <iasoline shovel, which loads 
into .S-ton cars. A ji'asoline motor lianls the cai-s from tlie ])it and 
delivers the clay to two hoppers at the ])Iant. 

From the hojjpers the clay is delivered l»y two ])ai'allel belt con- 
veyors to two dry i)ans. The ])roduct from the i)ans is elevated by two 
bucket elevatoi's to two wire screens, which deliver the nndersi/e to a 
centi'al hopper, and return the oversize to the dry pans. From the 
hoppers, the clay is fed to a ])ng-mill, then to an au<i('r machine, 
eqni])i)ed with a wire cutter. 

From the take-off belt followinii- the wire cutter, the brick are loaded 
on drier cars. A 16-track tunnel di'ier is used, which is 120 feet lonii, 
60 feet wide, and 6 feet high, and has a capacity of 7o,()()() brick \)ov 
60 hours. Two Iladfield-Penfield blowers, driven by a .")(l-li.p. motor, 
circulate heated air from an oil-fired furnace to the drier. 

Six natural-gas-fired held kilns are in use, having a capacity of ToO,- 
000 to 1,000,000 brick each. 

.Machinery in the plant is driven by a IfiO-h.p. Western gas engine. 
Tlie plant operates tlironghout the year, and 40 men are employed. 

Ciilifoniia Clan Piuducfs Co. Victor Kremer, president. "Victor 
Kremer Enteri)rises, Inc.," 315 West Mutual Life ]>uilding, 321 
West Third Street, Los Angeles. The plant is in South Gate. This 
factory manufactures an extensive line of glazed wall tile and ceramic 
floor tile. English china and ball clays are used in the white-burning 
bodies, but Lincoln clay (sample Xo. 146, p. 303) from Placer County 
and Cardiff fire clay (sample No. 36, p. 311) from the company's 
property in San Diego county are used in the cream, buff and darker- 
colored bodies. 

The finer cla\s to be used in the manufacture of white bodies and 
other high grade ware, are ])repared by blunging and filter pressing 
the ground material. Plastic clay mixtures are prepared in ])ug mills, 
and ai'e well seasoned before use. 

Dry-pressed floor and wall tile are made in hand-operated ])resses. 
PMoor and wall tile with an undulating surface are produced by hand 
l)ressing of pugged clay in ])laster molds. The latter are highly prized 
by architects to secure certain artistic effects, as the undulating sur- 
face gives the impression of wear resulting from long use. 

Drying is done Avith hot air, in-oduced by waste heat. The drying 
time varies from 24 to 36 hours depending upon the size of tile. 

^lonochrome glazes are api)lied by hand dipping in the glaze slip. 
Polychrome work is done with a glaze bulb. Some brush work is 
done in special cases. 

All of the glazed tile are given a double firing. There are three 
biscuit kilns with a firing cycle of 72 to 90 hours to attain a maximum 
temperature of 2400" F. Three glost kilns are in use, with a firing cycle 
of 36 hours to 1800" F. The apparent discrepancy in the capacities 
of the biscuit and glost kilns is explained by noting that the tile are 
packed in sand in the biscuit kiln saggers, but must be supported on 



100 DIVISION OF MINES AND MiNI^fG 

pins in the glost sagjj:ers, hence requiring- more space per nnit of tile 
area in the latter case. 

]\Inch of the work in the factory, sucli as api)lyin«? glazes, removing 
loose dust from tile after dry pressing, packing and unpacking of 
saggers, etc., is of such a nature that Avomen employees are used, men 
being employed only for the heavier duties, such as operating the 
presses, trucking, kiln setting or drawing, and firing. 

City B)'ick Co. The plant is at 1900 West Manchester Avenue, 
(Eighty-sixth Street) and Western Street. This company makes 
common red brick only. The clay in use is a surface deposit of loose 
sandy loam, with just sufficient bonding ])ower to ^lermit the manu- 
facture of a satisfactory building brick by the soft-mud process. The 
clay is mined in a shallow pit by horse scrapers, wliich deliver the 
material to an incline tram whicli dumps into a hopper feeding a 
disintegrator and pug mill, followed by a 6-brick press. The brick 
are carried to the drying sheds by rope conveyors. The dried brick 
are fired in gas-fired open kilns. Handling losses are apparently 
higher than in most i^lants, on account of the low strength of the brick 
in the plastic and dry state. 

Claycraft Potteries, Inc. Gus Larsen, president; F. H. Koberts, vice 
president; W. C. Reordan, treasurer; Henry Prussiing, secretary. 
Office and plant at 3101 South Fernando Road, Los Angeles. This 
company manufactures faience art tile, using an Alberhill clay body 
that matures at cone 5 (1180° C.) and applving glazes that mature at 
cone 4 (1050° C). 

The plant is equipped with two 8-ft. wet pans, two tile augers, a 
sagger press and three tile presses, one of which is power-driven and 
has a capacity of 900 tile per hour. All fancy i)ieces are hand-molded 
in plaster molds. 

The ware is dried in three 6-ft. by 7-ft. by 25-ft. tunnel driers. The 
biscuit firing is done in three '220-ft. round down-draft kilns, gas 
fired. Three muffle kilns are used for the giost firing. 

Twenty-five men are employed. 

H. F. Coors Co., Inc., H. F. Coors, manager. P. 0. Box 517, Ingle- 
wood. This plant is at 419 South Judah Street, Inglewood. It was 
established in December, 1925, for the manufacture of porcelain plumb- 
ing accessories and electrical specialties. 

English china clay and Coors ball clay (sample No. 57, p. 264), 
Campo or Kingman feldspar, and various grades of silica are used 
in the ])()dy mixture, which is prepared by ball-mill grinding. 

Some of the ware is dry -pressed, and some is cast. A hot-air drier 
is used. An 8-foot gas-fired round down-draft kiln is used for both 
the biscuit and the glost firing. A small muffle kiln is used for decorat- 
ing, which consists principally of labeling faucet handles. 

Davidson Brick Co. Nathan Davidson, owner, 5301 Chicago Avenue, 
Los Angeles. This is a well-equipped and Avell-arranged plant for 
manufacturing (Common red brick. The clay varies from an adobe 
to a soft clay shale. Mining operations have exposed a bank 60 to 70 
feet high, and 300 feet long. The pit extends into a gentlj^-sloping hill- 
side above the plant. An electric shovel is used for mining and loading 
into dump cars, which are hauled to the i)lant by a gasoline locomotive. 



CLAY RESOURCES AND CERAMIC INDUSTRY 101 

Brick are made by the stiff-mud, side-cut process. A rope conveyor 
is used to deliver the brick to the drying sheds. Oil fired field kilns 
are used. 

A sam])le (No. 60) of the more shaly variety of clay was taken as 
i-epresentative of the class of material to be expected in this district. 
The tests (p. o-tO) indicate that the drying and firing jjroperties of 
the clay are not greatly different from those of the Santa Monica 
clay (sample No. 61, p. 841), which is widely used in Los Angeles 
County as an ingredient of sewer pipe, conduit, flower pot, and olla 
mixtures. 

Empire China Compunj). Office and plant at Burbank. ]\Ir. ]\Ior- 
gan, superintendent. This is a well-equipped plant, containing seven 
round down-draft kilns that operated for a number of years for the 
manufacture of semi-porcelain hotel and dinner china. Experiments 
have been in ])rogress for a number of monllis on tlie manufacture of 
vitreous dinnerware, and the management expects to start production 
of this ware during the si)ring of 1928, using a California feldspar and 
silica, Nevada china clay, and a certain amount of Florida clay.^ 

I'J)nsro Rrfractorics Conipanij. E. M. Smith, president. Office and 
plant in Southgate, at Manchester Avenue and Atlantic Boulevard. 
This company was established in 1927, and was not visited by the 
author, such data as are included here having been supplied by the 
com{)any. The company manufactures fire brick, silica brick and glass- 
tank refractories. The clays are obtained from El Toro, Orange 
County. (Hunter Ranch ?, see samples No. 63, 64 and 268, p. 260), 
and from the Emsco pit in the Alberhill district, Riverside County. 
Eight gas-fired kilns are in use. 

Gladding, McBean and Companij. Southern Division. Atholl 
^McBean, ])resident; Fred B. Ortman, vice president. Los Angeles office 
at 621 South Hope Street. In 1926 this com])any merged with the 
Los Angeles Pressed Brick Company. The Southern Division of the 
com])any includes the following ])lants : the Alberhill (see under River- 
side County), Santa ]\Ionica and Los Angeles plants, all formerly owned 
by the Los Angeles Pressed Brick Company ; and the Tropico plant. 
The company also owns the Goat Ranch clay deposit in Orange County 
(see under Orange County). 

Los Angeles Plant. 952 Date Street, Los Angeles. This is the 
largest of the plants formerly owned by the Los Angeles Pressed Brick 
Com])any, and has perhaps the greatest manufacturing resources of the 
southern California plants of Gladding, McBean and Company. The 
])roducts made at this plant are terra cotta, face brick, 'quarry' tile, 
and roofing tile. The plant is in the heart of the Los Angeles com- 
mercial district and all clay must be shipped in. 

The terra cotta mixtures are the same as tho.se in use at the Tropico 
plant, described below, and are prepared in the same manner by dry 
pans and pug-mills, followed by a variable period of seasoning in waste- 
heat humidifiers. 

The face brick mixtures consist of varying proportions of Santa 
IMonica red-burning clay and a number of varieties of Alberhill clay. 
The face brick production of this plant is the second largest in the 

* G. Ray Boggs, private communication, December S, 19".7. 



102 DIVISION OF MINES AND MINING 

Gladding, McBean organization. A wide range of colors and textures 
are ])rodnced. 

Quarry tile are Jiaiul made from mixes similar to those used for face 
brick, and are produced in a wide range of red colors. The product is 
knoAvn as 'Palacio' tile. 

Practically all of the roofing tile produced by the Southern division 
and approxinuitely 60% of that manufactured by all of tlie comi)any's 
l)lants is made at the Los Angeles plant. Both machine and hand made 
tile are produced. The laboratory is constantly experimenting on new 
glazes and body mixes, and many distinctive effects have been produced. 

The jilant is well equipped. Practically all labor is ])erformed 
mechanically and all moving of material is done by motor. There are 
25 kilns, divided as follows : thirteen round down-draft kilns, four terra 
cotta muffle kilns, and eight rectangular mufflle kilns for enamel work.. 

Santa ^Monica Plant: Colorado Avenue and Twenty-fifth Street, 
Santa Monica. Formerly owned by the Los Angeles Pressed P)riek 
Company. The products are roofing tile, hollow tile, flue lining, chim- 
ney pipe, quarry tile, and brick. 

Most of the clay used is mined at the plant, which also supplies a 
large quantity of clay for the Los Angeles ])lant. The ])roi)erty includes 
45 acres of clay land. The deposit is similar to that in use by other 
manufacturers in this area, including the Western Brick Co., the 
Simons Brick Co., and the Santa Monica Brick Co. On the Gladding, 
McBean jiroperty the clay is from 10 to 36 feet thick, dii)ping north- 
westward, and increasing in depth in that direction, presunuibly under- 
lain by gravel. Sample No. 61 was taken from the stock ])ile in the 
])lant, and is an index of the type of material mined by this company 
and others in the district. The test results are on page 341. 

All products are made by the stiff-mud process, on auger machines. 
The quarry tile, known as 'Promenade' tile, is made in a wide variety 
of red tones, with here and there a purplish to greenish hue. 

Twelve round down-draft kilns are operated. 

Bibl: Bull. 88, ]). 214 (L. A. P. B. Co.), and p. 217 (Western Art 
Tile Works (now the Tropico plant). Prel. Rejit. 7, i)p. 53-56 (Los 
Angeles Pressed Brick Co.), and pp. 56-57 (Pacific Minerals 
and Chemical Co., now the Tropico plant). 

Tropico Plant : Located in Glendale. This plant was started in 
1902 as the Pacific Art Tile Company, the first factory of its kind west 
of the Rocky Mountains. After several reorganizations, the plant was 
eventually ac(|uired by Gladding, McBean & Com])any and in 1922 
the name was changed to its present form. The ]irincipal products 
of the plant are sewer pipe, flue lining, architectural terra cotta, and 
faience tile. 

Sewer Pipe: Tlie sewer pipe mixture contains red-burning common 
clay from Santa Monica (sam])le No. 61, p. 341), Emsco red (sample 
No. 72, p. 328), and one or more other clays from various sources. The 
clay is prejmred by dry pan and inig-mill, shaped in power-driven 
('steam) ])resses, dried on slatted floors, and fired in down-draft bee- 
hive kilns, fired with gas up to 1100-1300° P., and finished to cone 03, 
1980^ F., with oil. The smaller pipe is set two lengths high, and requires 
a firing schedule of 88 to 100 hours.' The larger pipe is set three high, 



CLAY RESOURCES AND CERAMIC INDUSTRY 103 

and r('(|uiiv.s a 12()-lionr firiii": schedule. The total kiln turnover is 
10 to 11 days. Thirty-two kilns are in u.se for sewer pipe and flue 
lining, each with a capacity of approximately 40 tons. 

Flue Linin<i': Tlie ])rincipal inj^redicnt of the flue liniuii' mixture is 
the white Enisco clay (sample No. 70, j). 272). 

Terra Cotta : Tho architectural terra cotta output of tliis i)hint is 
not lar<i-e at jire.sent, at least not of the order of majrnitude of the output 
at the Lincoln, Placer County, ])lant of the com|)any. Essentially the 
same terra cotta mixtures are used at Trojjic') as at Lincoln, the Lincoln 
clay (sample No. 157. p. ;504) beinii' shii)pe(l to Tropico for the purpose. 
The terra cotta mixture is prepared by dry pans and pu^' mills, fol- 
lowed by seasoninii' in humidified rooms for at least 24 hours before 
l)ressing'. Six kilns are in use for terra cotta, firinp: to cone 3 to 5. 

Tile: The faience tile is nuide by dry pressing a buff-burnin*; body 
similar to the terra cotta mixture, biscuited at cone 4, and glost at 
cone 05 and OG. The body is mixed and ground in dry pans, and shaped 
in screw i)resses, formerly operated by hand, but now entirely su])- 
planted by power driven presses. At the time of visit, July, 1925, 5 
bee-hive kilns were in use for tile. The biscuit kilns Avere operated on 
the same schedule as the terra cotta kilns, rerpiirinc' 100-110 hours 
firing, while the glost kilns operated on a 20-hour firing schedule. The 
glost kilns u.se oil exclusively. A small tunnel kiln for tile has since 
been installed in order to secure more uniform results, and to decrease 
the time cycle. 

Miscellany: This j)lant is continually progressing, and various 
improvements and economies arc being added from time to time, 
^lechanical handling of materials is in use wherever it is economic. 
The i)resent system of handling the ware is on hand trucks, running 
on tracks, in the sha])ing and glazing departments. A gasoline ti'actor 
is used for kiln-yard haulage. Eecording pyrometers with base metal 
cou])les are used for temperature control of the kilns. 

A laboratory is maintained to aid in the development of terra 
cotta glazes and bodies. 

Bibl: Cal. State Min. liur. P.uU. No. 38, p. 217 (Western Art 
Tile Works) ; Prel. Kept. No. 7, p. 56 (Pacific Minerals and 
Chemical Co.). 

Glohe Tile and Porcelain Works. P. C. Boving (formerly of the 
Pomona Tile Com])any), president and general manager. This plant 
was established in 1927 for the manufacture of ceramic floor tile. The 
plant has 15,000 square feet of floor space, and the capacity is 3000 
s(puire feet of tile per day.^ 

H d: H Tile Company. Ord Hagerman and V. K. Halieman. Rej)- 
resented by C. P. Johnson, Arcade Building, Los Angeles. This com- 
pany was organized in 1927 with a capitalization of $30,000, to produce 
ceramic tile." Further details are lacking at this writing. 

Italian Terra Cotta Co. W. H. Robinson, owner. Office and plant 
at 1149 Mission Road, Los Angeles. This is claimed to be the only plant 
on the Pacific Coast exclusively engaged in the manufacture of sculp- 
tured terra cotta garden pieces. 

' day-Worker, Xovember. 1926, p. 390. 
= Clay-Worker, August, 1927, p. 123. 



104 DIVISION OF MINES AND MINING 

The bodies are made from Alberhill pink mottled (sample Xo. 7, p. 
o28) and hill blue (sample Xo. 9, p. 287), and some Santa ^loniea clay 
(sample Xo. 61, p. 341), which produce a red body when fired. A slip 
f^laze, lifjht brown in color, is used on some pieces. The clays are pre- 
])ared by dry-pan <>rindinsr followed by a puij-mill. After sufficient 
seasouinp-, the pieces are shaped by hand pressing in plaster molds and 
air dried before firing. A gas-fired round down-draft kiln is used 
for firing, the heating schedule ranging from 68 to 72 hours. 

]\Iany of the models are imported from Spain and Italy. The 
market for the products is not confined to the Los Angeles district, 
as the artistic value of the ware has often imi)ressed visitors from 
other sections of the United States, and many pieces have been shipped 
to the eastern and middle western states. 

Bibl: Cal. State Miu. Bur. Prel. Kept. Xo. 7. ]). 51. 

K. & 31. Pottery. M. C. Myers, president. Oi^ice and plant at 2318 
East Fifty-second Street, Los Angeles.. 

This pottery makes stoneware from Alberhill clays, using the E-101, 
and the hill blue (sample X^o. 11, p. 257, and 9, p. 2S7) varieties. Ollas 
are also made from the pink-mottled clav from Alberhill (sample No. 
7. p. 328). 

The stoneware is made by turning and the glaze is applied to the 
dried ware before firing. 

The plant is equipped with three round down-draft gas-fired kilns, 
25 feet, 22 feet, and 15 feet in diameter, res]iectively. The annual 
wholesale value of the product is nearly $60,000. 

Bibl : Cal State Min. Bur. Prel. Kept. Xo. 7, p. 51. 

K and K Brick Company.^ 0. J. Cubach, president; II. D. 
Simons, secretary. Office. 801 ^Merchants X'ational Bank Building. Los 
Angeles. This company owns a 38-acre property in Bishop Canyon, 
Los Angeles, and manufactures common brick. 

The deposit consists of blue and gray plastic shale, 10 to 20 feet 
thick, underlying from two to five feet of adobe soil and gravel. The 
clay is mined by hand methods in an open cut, and is transported to 
the plant in small cars. 

The stiff-mud process is used. The plant is equipped with a dry pan, 
screens, pug-mill, and a Kaymond auger machine, with a wire cutter. 

The brick are dried in open drying sheds, and are fired in six open 
field kilns. Both natural gas and oil are used as fuel. 

The plant o]>erates throughout the year and 35 men are employed. 
Power is suii]ilied by a 250-h.p. boiler. The rated capacity of the plant 
is 75,000 brick per day. 

Bibl : State Min. Bur. Prel. Kept. 7, p. 51. 

La Cal Tile Company. Val Alden and Kittridge streets. Van X'uys. 
A recent report- states that this company was building a plant on the 
above site, at a cost of $70,000. Further details are lacking at this 
writing. 

Lindennan tf- Decker Company.'^ Address, Lomita. This is a firm 



^ Data .supplied by W. B. Tucker, district mining engineer, November, 1927. 
= Clay-W' orker, March, 1926, p. 207. 



CLAY RESOURCES AND CERAMIC INDUSTRY 105 

of general eontractoris who o\vii a lO-aere proi)erty at Harbor City 
that is now under lease to Mexicans, who are manufacturing hand-made 
i-oofing tile. 

The deposit consists of 10 to 15 foot of rod clay, overlain by one to 
to two feet of gravel. Hand methods of mining are used, and the clay 
is delivered to the tile plant bj^ a horso-drawn dump-cart. The clay is 
l)repared and the tile shaped by hand. Drying is done in tlie open aii-. 
A round gas-fired kiln is used for firing. 

Long Beach Brick Companji.^ H. A. Ilavnor, president; H. C. Arm- 
strong, secretary. Office at 154 Elm Street, Long Beach. The co)npany 
owns a 10-acre property at Harbor City, and manufactures common 
brick. 

The deposit consists of rod clay, 10 to 20 feet thick, covered by a 
maximum of two feet of gravel. The clay is mined b.y scrapers, and is 
transported to the plant by belt conveyors and Ford trucks. 

The equipment includes a dry pan, elevators, screens, American 
anger machine, and wire cutter. Drying is done in o]ion-air drying 
sheds. Rope conveyors are used to transport the brick to and from the 
drying ,vard. 

Six oi)en field kilns, firod with natural gas, are used. The ])lant 
usually operated during ton months of the year, employing 25 men. 
Electric power is used, the installed cai)acity being 200 h.p. The rated 
capacity of the plant is 45,000 brick per 8-hr. day. 

Bibl : Cal. State :\[in. Bur. Prcl. Kept. 7, p. 51. 

Los Angeles Brick Co. A. A. Conger, president; E. W. ]\Iurphy, 
vice president ; Henry Prussing, secretary ; Gustav Larsen, director in 
charge of operations; W. C. Roordan, director in charge of sales. 
Home office, 1078 ^Mission Road, Los Angeles. 

This company owns and operates three common-brick and hollow- 
tile yards in the Los Angeles district, and has recently built a plant 
at Alberhill to manufacture tile, fire brick, and other ])roducts (see 
under Riverside County, p. 174) from clays mined on their own pro]i- 
erties, acquired through the purchase of the holding.s of the California 
Clay IManufacturing Company. 

The Los Angeles brick yards are the ^lission Road ]ilant, at the 
corner of ^Mission and jMarengo streets, near the County Hospital; the 
Chavez Canon plant, in Chavez Cafion, west of Adobe street; and the 
Seventh Street plant, at East Seventh Street, on the corner of Utah 
Street. 

^IrssTOX Road Yard: This property comprises 15 acres. The clay 
is a surface material from 25 to 30 feet thick, underlain by five or 
six feet of sand. Common brick only are made at this plant, using 
the soft-mud, sand-mold process. The brick are air-dried, then fired 
in ojien field kilns, using gas as fuel. The average daily capacity of 
the yard is 80,000 brick. A Hoffman continuous kiln, fired with 
coal screenings was formerly in use, but has been dismantled. Rope 
conveyors are used to deliver tlie brick pallets from the ]U'esses to the 
drying yard. 

Chavez Caxon Yard: This is a 26-acre property. The clay is a 
thin-bedded Puente (Lower Miocene) shale, forming a bank over 100 

'Data supplied by W. B, Tucker, district mining engineer, November, 1927. 



106 



DIVISION OP MINES AND MINING 




'J 



0/ 



r5 






a 

o 

O 



o 



O 



O 

o 

o 
W 
CM 



CLAY RESOURCES AND CERAMIC INDUSTRY 107 

feet lii^li, and dipping: southward into the hill. Tiie individual beds 
of shale vary from a very fine-.trrained plastic clay, to a sand, the 
different phases being ])resent in such jn-oportions as to make an 
excellent material for brick and hollow tile. The clay is mined by a 
team and scra])er, dumped into a hoi)per, delivered to a ear, which 
is hauled up into the ])lant by an electric hoist. The clay is ground 
in a dry pan, and fed by belt conveyors to ])Ug-mills and auucr machines. 
The bricks are dried in driers heated with steam from auxiliary boilers. 
Firing is done in open field kilns, with gas fuel. The capacity of the 
plant is 80,0()() brick and 100 tons of hollow building tile per day. 

Seventh Street Yard: This yard is 12 acres in area. The clay 
belongs to the upper ])ortion of the Boyles Heights Terrace formation. 
The soft-mud ])roeess was used, followed by air drying, and firing in 
open field kilns. It is i)robable that this i)roperty Avill be sold, as 
it has become too valuable for industrial i)roi)erty to Avarrant its 
continuance as a brick yard. 

IJibl: Cal. State Min. Bur. Prel. Kept. No. 7, p. 52. 

Malihu P(jfttries. Owned and operated by the ]\Iarblehead Land Co. ; 
R. B. Keeler, plant manager, P. O. Box, 518, Santa Monica. The plant 
is on the Coast highway, north of Santa Monica. The products of 
the plant are plain and decorated wall tile, made from a terra cotta 
body. A vieAV of the plant is given on ])hoto No. 16. 

A variety of clays are used, including a number of clays from the 
]\Ialibu Ranch, some Alberhill clays, and Engli.sh ball clay. The mixes 
are prepared by grinding in a 4-ft. dry pan, elevating to a bin, screen- 
ing, and ]iug-milling. followed by six weeks ageing. ]Most of the tile 
are shai)ed in a ^fuller tile auger, but some are liand-i)ressed in plaster 
molds. Saggers and tile setters are made at the plant, by hand. 

A Carrier drier, oi>erating on an 18-hour cycle, is used for drying 
the tile. The saggers and setters are dried in the open. 

Three up-draft kilns are in use. On biscuit firing, 10,000 sq. ft. of 
tile can be loaded per kiln, and the entire firing cycle takes one week. 
The finishing tem])erature is 2300'' F., which is reached in 96 hours 
fi-om the start of firing. On glost firing, each kiln holds 5000 sq. ft. of 
tile, the finishing temperature is 1600° F., the firing occupies 48 hours, 
and the entire cycle takes four days. Normally, one kiln is on biscuit 
firing, one is on glost firing, and the third is used for either, according 
to conditions. The kilns are fired with oil, atomized by air. 

Mission Brick Companij.^ ]Mrs. A. E. L. Anderson, 755^ Santa 
]\Ionica Boulevard, Los Angeles, owner. Joseph F. Reutera, manager. 
Office and plant at 6140 Scpulveda Boulevard, Van Nuys. The product 
of the plant is common red brick. The i)roperty consists of five acres 
of land, containing a bed of red clay from 5 to 20 feet thick, overlain 
b\- from one to two feet of soil. Mining is done in an open pit, using 
scrapers which are hauled by a Fordson tractor to a hopper which feeds 
a belt conveyor delivering to a bin at the plant. The soft-mud process 
is used. The plant is equipped Avith a pug-mill and a Quaker brick 
]:>ress, Avhich has a capacity of 20,000 brick ])er day. The brick are 
dried under sheds, to which they are transported in hand trucks. 



' Data supplied by W. B. Tucker, district mining engineer, December, 1927. 



108 



DIVISION OP MINES AND MINING 




o 
O 
m 

CD 
I— t 
0) 

C 

CO 

o 



o 






1-1 



So 

So 

^^ 

Cm 
o- 

a 

u 
o 
o 

be 

.s 



o 

z 

o 
o 

a 



CLAf RESOURCES AND CERAlSflC INDUSTRY 109 

Two ji:a.s-fired field kilns arc used. liavin<;' a eai)ac-ily of 50,()()() bricks 
each. Electric power is used in llic j>lant, the installed capacity being 
60 h.p. Twenty men are employed (luring llic operatinjr season, whicli 
is usually four months. 

Mission China Conijxinn. Victor Ki'enior, i)residcnt ; Jas. Tiffany, 
manager. General offices at .3121 W. Third Street, Los Angeles. Plant 
at 652 S. Griffin Avenue. Tiiis ])lant has been manufacturing semi- 
jiorcelain hotel and dinner ware for a number of years. The raw 
materials in use are P]uglisli china and ball clay, Edgar (Florida) 
kaolin, and California feldspar and silica. 

The body mix is prepared by screening through 150-mesh, blunging, 
filter-pressing, and pugging. ]Most of the ware is shaped by jiggering, 
but casting is used on the more complicated shapes. Steam drivers 
are used, operating on a 12-hour cycle. Saggers arc molded by hand at 
the plant. 

The biscuit ware is fired in two 17-ft. 6-in. up-draft kilns, to a finish- 
ing temperature of cone S (1225° C), requiring 55 to 60 hours. The 
ware is then dipped in glaze, and fired in two 16-ft. glost kilns to cone 
5 (1180° C), in 30 to 35 hours. Two days are required for cooling 
both tyi^es of kilns. The paper transfer process of decorating is used, 
and the decoration is fired on at cone 016 (735° C). Two decorating 
kilns are in use, which are fired in 12 to 14 hours, the entire cycle 
requiring 30 hours. All kilns are fired with natural gas. 

Fifty men and women are employed in the plant. IMost of the work 
is i)aid by piece rates, which are the same as those established in eastern 
potteries. 

Pacific Clinj Ptuducts Co.^ William I^acy, president; Robert Linton, 
vice president and general manager; W. R. Faw^eett, secretary- 
treasurer; Wm. McClintock, general superintendent. Main office, 1151 
South Broadway, Los Angeles. This company owns and operates three 
factories in Los Angeles district and several clay proi)crties in River- 
side and San Diego counties. The present company supersedes the 
Pacific Seiver Pipe Company whicli was formed some years ago by 
consolidating several smaller companies situated in Los Angeles, Corona, 
and Elsinore, these smaller companies having started business around 
1880 to 1885. 

Clay Properties : The company owns and operates the following clay 
mines : 

Name Shipping point 

Douglas.s Alberhill, Riverside County 

McKnight Corona, Riverside County 

Wildomar Wildomar, Riverside County 

'Hoist Pit KIsinore, Riverside County 

Kelly No. 1 Farr, San Diego County 

' The company owns a one-half interest in this property. 

In addition the company operates under lease several properties in 
Orange and San Diego counties ; also owns and holds in reserve for 
future operations five additional tracts in Riverside and San Diego 
counties. The total clay lands owned outright total 625 acres. The 
bulk of the clays used in the company's plants come from its own 
mines, although some are purchased from the Alberhill Coal and Clay 

' Description prepared by the company. 



110 



DIVISION OP MINES AND MINING 




ft 



o 



3 
O 
o 

>. 

o 
o 



be 



O 



o 
O 

CO 

■o 

O 



O 
o 

£ 

o 



ft 



.5? 

'S 

w 






o 
o 

H 
O 

W 



CLAY RESOURCES AXD CERAMIC INDUSTRY 1 1 1 

Comp.iny, the Enisco Chiy ('oiiii);my, and llie Lincoln Clay Products 
Company. Many difforont clays cntci- into tlic manufacture of the 
various products nuide, wliicli include s(>\ver pipe, electrical conduit, 
face brick, enameled brick and tile, fire brick and refractory shapes, 
firechiy. flue lininji' and ^as flues, drain tile, stoneware, earthenware 
water coolers and other articles. 

Plants: Three factories are operated at ])resent, viz, the Lincoln 
TIeifrhts plant. Avenue TAventy-six and ILunboldt Avenue, Los Ang-eles; 
the Slauson plant. Slauson and McKinley avenues, Los Anii'eles, and 
the Los Xietos plant on the eastern edg'e of the Santa Fe Sprinfi's oil 
field. The plants have a combined cai)acity of over 90,000 tons of clay 
]n'oducts per year. A ])lant at Terra Cotta, near Elsinore, and two 
l)lants at Corona Avere also formerly 0])erated. GeiU'ral views of the 
Lincoln Heights and the Los Nietos i)lants are shown on photos No. 18 
and 19. 

Lincoln Heights Plant .- J. L. Davies, sui)erintendent. This factory 
was built about 1890 and was equi]>ped to manufacture sewer pipe, 
brick and stoneware. At ]iresent it com])rises a brick department 
in-oducinji' face brick, enamel brick and tile, fire brick and refractory 
shapes and roofin<]: tile ; and a stoneware department making' a com- 
])i-ehensive line of grey earthenware, ollas, mixing bowls, etc. 

Clays for the stoneware are selected with esjiecial reference to 
producing a body as dense and impervious as possible; for ollas, or 
self-cooling water jars, the body should be slightly porous, since the 
cooling comes from evaporation of water which percolates through the 
jar to the outer surface. The mixes are finely ground in a Raymond 
hammer i)ulverizer, the dust being lifted by a suction fan a height of 
10 feet to the pug-mill feeder. The pugged clay is allowed to soak in 
the 'sweating room' for 24 hours or more, then goes to the jig rooms 
where there are 9 potters' wheels suitable for making all kinds of 
turned ])ottery up to a 12-gallon jar. The ware is dried in steam- 
heated dryers, then dipped in the proper glaze. Some of the stone- 
ware is given a biscuit firing before glazing, but most of it is made at 
a single bui'ning. using a slip glaze wliich niatures at the same tem])era- 
ture as the body. The stoneware bodies mature at about cone 8, and 
are a cream or light yellow color. Saggers made at the plant are used 
for some of the ware, chiefly for sup])ort. but as much ware as possible^ 
is open fired. There are o kilns 20 to 24 feet diameter used for 
stoneware. 

The brick department equipment consists of 3 dry pans. Hummer 
screens, 2 pug-mills, 2 auger machines, tAvo 14-brick American cutters, 
2 rejiresses, 2 humidity di-yers holding 40,000 brick each, an ovei'head 
traveling crane Avith clam shell for clay unloading, 2 electric lift trucks 
Avith i)allets for handling brick, and 11 kilns 80 feet diameter. The 
cai)acity is 40.000 brick per day. 

A AucAv of the clay bins and unloading crane is shoAvn on photo No. 20, 
and a pug-mill, auger machine and cutter is shown on photo No. 21. 

The stiff-mud brick — comprising the rough and smooth texture wire 
cut face brick and re-pressed Avire cut fire brick — are dried in the 
humidity dryers in 42 hours. About 6 days are required for the firing, 
the finishing temperature being about 2100^. Dry press brick go 
directly to the kilns Avithout preliminarA^ drying, and are burned to 



112 



DIVISION OF MINES AND MINING 




n 



>, 
m 

3 

o 
o 

>, 



o 



o 



c 

<; 

CO 

o 



o 
O 



o 
3 

■a 
p 

>. 

d 

O 
o 

'3 



c 



(0 

o 

O 

0) 



0) 

p. 



o 

z; 

o 
o 

0^ 



CLAY RESOURCES AND CERAMIC INDUSTRY 



113 



about 2050^. Enaincl brick are made on biscuit, or bui'iied ])ressed 
brick, whicli are coated with enamel slips and buiMied a second time to 
mature the glaze. 

A variety of very attractive shades of red, tan, g'rey and other colors 
is made in the wire-cut brick. Present architectural practice favors 
eombininji- ditferent shades and colors, following the impressionistic 
idea, and tliese combinations are ])roved very effective in lending 
distinction to face-brick buildings. The Pacific enamel brick is in 
wide deiiiaiid and is ship|)ed to all tlie Pacific Coast states as well as 
abroad. 

A comph'te line of fire bi'ick and i-clVactorics is also inanufactui'ed. 
Three grades of standard fire-brick are made, with softening points of 




Photo No. 20. Clay bins and unloading crane, Lincoln Heights plant, Pacific 
Clay Products Co., Los Angeles. (Photo by courtesy of the company.) 

about 3200° F., 3100° P. and 3000° F., respectively. The highest 
grade brick is hand molded, the others made on the auger machine and 
repressed. They are burned to about 2500" F. 

Roofing tile are also made, using a combination Hummer machine. 
They are dried on waste heat drying floors and burned in the brick 
kilns. 

Over 20 different clays are used at this jilant, coming from Riverside, 
Orange, San Diego, Los Angeles, and Placer counties. The plant site 
comprises over six acres, and lies between main lines of the Santa Fe 
and Union Pacific railroads, having sidings from each. The plant is 

8 — 54979 



114 



DIVISION OP MINES AND MINING 



equipped to use either natural gas or fuel oil. Machinery is all motor- 
driven. About 130 men are employed. 

The company's laboratories are located at tliis plant and are fully 
equipped for chemical and testing- work. A high temperature testing 
kiln capable of heating up to 3400'' F., is used for testing fire brick. 
Routine testing for color and shrinkage is regularly carried on. All 
kilns are equipped with pyrometers which are used for control in 
connection with Orton standard cones. 

Los NiETOS Plant : Cecil V. McClintock, superintendent. The Los 
Nietos factory is the largest and newest of the plants, and is situated 




I'HOTO No. 21. Pug-mill, auger machine and cutter, Lincoln Heights plant, 
Pacifle Clay Products Co., Los Angeles. (Photo by courtesy of the company.) 



on a 46-acre tract on the edge of the Santa Fe Springs oil field. It is 
a thoroughly modern, well-arranged plant. Sewer pipe is the principal 
product, but electric conduit segmental sewer blocks and lining blocks, 
drain tile and flue lining are also made. 

The plant makes sewer pipe, electric conduit, roofing tile, drain 
tile, flue lining and gas flues. Clays are shipped in from Riverside and 
San Diego counties and some clay mined on the premises is also used. 

The equipment comprises three 9-ft. American dry pans, 2 pulver- 
izers, gravity screens, four 8-ft. American wet pans, one 14-ft. pug-mill. 



CLAY RESOURCES AND CERAMIC INDUSTRY 



115 



3 sewer-pipe presses, 1 aiip-er machine, and .'}() riituhu- down-draft kilns 
30 and 34 feet dianietei-. Some of the dry and wet pans are sliown on 
])hoto No. '22, and one of llie s(>wei'-pipe presses is sliown on i)hoto No. 
23. The dryinji' Hoor is 220 x !t20 ft. and is shown on photo No. 17. 
There is a \vell-equi|)i)('d machine shoj) and testing ])laii1 foi- sewer i)ipe. 
Steam is fni'nislied from two 250-h.p. IJaheock and Wik'ox boilers, with 
three 150-h.p. luhuhir hoik^rs as stand-by. Excepting tlie steam-driven 
sewer-pipe presses all e(inipment is driven by electric motors. Natural 
gas and oil are both used for fuel. 

Clays are shipped in from Riverside and San Diego counties and 
used in connection with red shale mined on the i)remiscs. The clay 
track is elevated above the storage bins so that the clays are dumped 




Photo No. 22. Dry pans and twin wet pans, T^os Nietos plant, Pacific Clay 
Products Co., I^os Angeles Couiily. (Photo by courtesy of the company.) 



directly from the ears at minimum cost. Some of them require fine 
grinding which is done by regrinding the oversize from the screens in 
pulverizers of the squirrel-cage type. 

The drying room is equipped with steam-heating pipes overhead and 
underneath the floor, affording very satisfactory control. From 2 to 
15 days is required to dry the ware, depending upon the size. Firing 
time varies likewise from 3 to 8 days. The bodies mature at 2100° F. 
to 2200° F. The salt glazing is done during the last two hours of the 
firing, i. e., when the kiln is at maximum heat, by throwing a shovelful 
of salt into each fire-box every fifteen minutes. The salt volatilizes, is 
carried through and around the hot pipe, and as the vapor comes in 



116 



DIVISION OP MINES AND MINING 



contact with the clay the alkali in the salt combines with the silica of 
Ihe clay to form the ^laze on the surface. 

All sizes of sewer pipe up to aiul including 80-inch are made. Seg- 
mental blocks for making sewers of larger size are also among the 
products. The plant emi)loys 150 men. 

The i)lant is served by both Santa Fe and Southern Pacific railroads, 
having sidings connecting directly with each. 

Slauson Avenue Plant : Roy Lacy, superintendent. The Slauson 
Avenue plant was built about 1885. It is located on a tract of six 
acres on McKinley Avenue from Slauson Avenue to Fifty-third Street. 
It is served by the Santa Fe Railroad, the plant sidings connecting 




Photo No. 23. Sewer-pipe press, Los Nietos plant, Pacific Clay Products Co., 
Los Angeles County. (Photo by courtesy of the company.) 

with the tracks on Slauson Avenue. Equipment consists of a conveyor 
unloader for clay, 2 dry pans, pug-mill, double-shaft auger machine, 
and sewer-pipe press. There are seven 30-foot kilns and one 28-foot. 

Pomona Brick Company.'' E. G. Stahlman, president; H. F. Stahl- 
man, secretary. Address, Pomona. This company owns a 10-acre 
property on West Ninth Street, Pomona, and manufactures common 
brick. 

The dei)osit consists of red sandy clay, 8 to 20 feet thick, without over- 
burden. The clay is loaded by a small steam shovel into trucks. 

The plant equipment includes a dry ])an, screens, pug-mills, and a 

' Data supplied by W. B. Tucker, district mining engineer, November, 1927. 



CLAY RESOURCES AND CERAMIC INDUSTRY 117 

Potts brick pi'ess. Tlie brick are conveyed to a (lryiii«i' yard on rope 
conveyors. Five field kilns, fired with natural ^as, are in use. 

The plant operates during about six months of the year, and employs 
14 men during that jieriod. About IK^ h.p. of steam ))ower are required. 
The rated capacity of the jilant is ;W,0()() brick i)er 8-hi-. day. 

Bibl: Cal. State Min. Bur. Prel. Kept. 7. j). 58. 

Puinona Tile Manufacturin<i ('oiiip(ni>i, Tliird and Reservoir streets, 
Pomona. R. J. Scliroeder, j^residt-nt and treasurer; C. V. Svendsen, 
superintendent. This company manufactures ceramic floor and wall 
tile, using Edgar clay from Florida, English china clay, California and 
Arizona feldspar, California silica, and some Santa ^Monica clay where 
red-burning bodies are re(iuired. Albci-hiii and Lincoln clays are used 
for saggers. 

The tile are shaped in hand-operated dry presses. At the time of 
visit. July, 1925, two down-draft kilns were in opei'ation, and a third 
kiln for increasing the capacity by HO'^f was under construction. Gas is 
used for fuel, with oil in reserve. The kilns are fired to cone 11. 

The plant emj^loys from 40 to 45 employees, mostly women and girls, 
Avho do the Avork of packing and un])ackinu- the saggers, cleaning the 
tile after firing, and pasting them on paper. 

Poxon Pottery. G. J. Poxon, president ; Earl Lincoln, foreman. 
Offices 2300 East Fifty-second Street, Los Angeles. This pottery makes 
a complete line of plain and decorated table ware. All of the clays 
used are imported from England. The im])orts amount to about 1000 
tons per year of ball and china clay. Feldspar and silica of the best 
quality are obtained from various sources in southern California, 
mainly from Riverside County. 

After coarse-crushing to about Y' size, the silica and feldspar are 
mixed in the proper ]n'0]iortion with the clays, and the grinding is 
finished in a wet ])uli). The mix is tlien passed to filter presses for the 
removal of excess moisture, and the filter cake is then ready for 
shaping. 

Power-driven wheels are used tliroughout for all shapes that can be 
made mechanically. After shaping, the ware is dried for about three 
hours in gas-heated drying rooms, or for a longer time in the factory 
atmosphere. 

The biscuit firing is done in gas-fired kilns at a temperature of 
2300° F., for 70 hours. After cooling, the ware is dipped in the 
glazing material, and fired for 30 hours at 1800" F. 

Some of the decorating is done by the paper-transferring ])rocess, 
while the higher-])riced ware is hand-decorated. After decorating, the 
ware is fired for 12 hours at about 1100= F. 

Seven gas-fired kilns are in use. The factory produces about 1500 
dozen pieces per day, and employs 70 men and women. 

Some ten years ago this plant used California clays, but found that 
the English clays gave better results. Kaolin from Hart, San Ber- 
nardino County, has been used recently, but is said to be too variable. 
Clay from Amador County has been tested with good results. 

In 1926, the company built a new plant at Slauson and Miles ave- 
nues, in Vernon. It is understood that both i)lants will be operated, 
but further details are lacking at this writing. 



118 DIVISION OF MINES AND MINING 

St. Louis Fire Brick and Clay Co. Joseph Mesmer, president ; A. J. 
Mesmer, superintendent. Office and plant at 2464 E. Ninth Street. Los 
Angeles. This eompanj^ manufactures fire brick. Practically all of 
the clays in use at present are purchased from various sources, but the 
company owns a deposit near Corona that has been worked at various 
times in the past. The principal clays in use are the select main tunnel 
(sample No. 15, p. 264) and west blue (sample No. 23, ]). 277) from 
Alberliill ; the Emsco pink mottled (sample No. 71, p. 278) and the Lin- 
coln, No. 1-6 (sam])le No. 146. ]). 308). Some experiments were made 
with the Weiss clay from Glen Ellen, Sonoma County (samples No. 
194 and 195, p. 262), but difficulties were encountered in securing satis- 
factory stnength. 

Both the auger and hand-pressing processes are in use, and the brick 
are fired in three down-draft bee-hive kilns, and two rectangular kilns, 
using oil as fuel. 



"^o 



Bibl: Cal. State Min. Bur. Prel. Kept. 7, p. 58. 

Santa Monica Brick Company.'^ E. A. Douglas, president; F. ^M. 
Taylor, vice president and treasurer. Office and plant at Twenty-third 
and Michigan streets, Santa Monica. The company owns 10 acres of 
clay land and manufactures common brick, red face brick, roofing tile, 
and red floor tile. 

The clay is a plastic, red-burning clay, underlying an extensive area 
from which numerous other manufacturers in the Los Angeles district 
secure clay for brick, hollow tile, roofing tile, and sewer pipe manufac- 
ture. There is no overburden. The deposit is now (1927) being 
worked by a power shovel against a 45-ft. bank, but the height of the 
bank may be increased in the future to 75 feet. The clay is trans- 
l)orted to the plant in cars operated by an endless cable hoist. 

Tlie plant is equipped with a 60-h.p. 24-in. by 24-in. American dis- 
integrator, a 150-li.p. American auger machine, having a rated capacity 
of 75.000 brick per day, an American automatic brick cutter, a 40-h.p. 
Pate-Koot-Heath roofing-tile auger, having a rated capacity of 10,000 
tile per day, and a hand-operated roofing-tile cutter, in addition to the 
necessary elevating and conveying equipment. 

A hot-air tunnel drier is used, which operates on a schedule of 36 
hours. Ten up-draft field kilns with permanent walls are used for 
firing. Both natural gas and steam-atomized oil are used. Normally, 
four kilns each with a capacity of 500,000, are used for firing brick, 
five kilns of 15,000 capacity each are used for roofing tile, and one kiln 
of 1000 sq. ft. capacity is used for floor tile. The brick are water 
smoked for three days, fired for four days, and allowed to cool for three 
(lays. Drawing and setting require about seven days. The finishing 
temi)erature at the end of the firing period is approximately cone 07 
(975° C, or 1787° F.). The tile are water smoked for one day, fired 
for three days, and cooled in two days. One day is sufficient for setting 
and drawing. 

The company also makes liand-made ]\Iission roofing tile, which are 
dried in the open air. 

The plant is operated throughout the year, employing 60 men. A 
total of 350 h.p. of electric power is installed in the plant. The rated 

' Data supplied through the courtesy of the company. 



CLAY RESOURCES AND CERAMIC INDUSTRY 119 

c'aj)aeity of tl\e plant is T.l.OOU l)riek and 40 .s(iuares (lUU square ieet 
each) of roofin«r tile per day. 

Simona Brick Co. Walter R. Simons, president ; Robt. P. Isitt, vice 
president ; H. B. Howeth, secretary ; J. T. Crampton, treasurer. Office 
at 125 West Third Street, Los Angeles. 

Boyle Plant: The r>oylo i)lajit of the Simons company occupies 
a .^O-aere ])roperty at 1117 South IJoyk' Avenue, on the east bank of 
the Los Angeles River, a few blocks south of the Seventh Street yard of 
the Los Angeles Brick Co. Tliis plant is now engaged in the manu- 
facture of roofing tile exclusively. The claj' deposits on the property 
have been worked out by past operations, at least to such an extent 
that it is more economical to ship clay to this plant from the company's 
large pit at Santa ]\Iouica. Tn order to produce the wide variety of 
colors demanded by the trade of today, varying amounts of Emsco 
white i)lastic (sample No. 70. \). 272) and other clays fi-oin the Alberhill 
district are mixed with the Santa Monica material. Most of the ware 
is red, and the mixture for this ])ro(luet contains 75% Santa Monica 
clay and 25% of a pink burning fire clay, such as Emsco pink mottled 
(sam])I(' Xo. 71, p. 278). Liglit i)i]ik, cream, and buff tile are produced 
by adding \\\) to 90% of a light burning fire clay. 

The tile are formed by the stiff-mud process, with Mueller machines. 
Drying under .sheds requires nearly a Aveek. Firing is done in 12 
down-draft bee-hive kilns. The lighter-colored tile, containing more 
refi-actory clay than the i-ed burned variety, are fired in one compart- 
ment of a double rectangular kiln, the dimensions of each compartment 
being 6 ft. by 20 ft. by 8 ft. A temperature of 2500° F. is required, 
and the heating period occupies three days. Kiln slabs, for supporting 
the tile during firing, are made of a mixture high in refractory clays, 
and are fired in the other compartment of the double rectangular kiln. 

Saxta Monica Plant: This plant is at Colorado Avenue and 
Twentj'-sixth .street, Santa jMonica. The property consists of 24 acres. 
The clay is similar to that on other properties in the same area ; see 
under Gladding, McBean and Company, Santa Monica Brick Company, 
and others. The soft-mud process is u.sed and the brick are fired in 
oil-fired field kilns. 

Simons Plant : The Simons ]ilant is advertised as being the largest 
plant in the world exclusively devoted to the manufacture of common 
brick. It is situated on a 400-acre tract at Simons, on the main line 
of the Santa Fe Railroad, 1 1 miles northeast of Montebello on the 
Southern Pacific Railroad. 

The clay is of excellent quality for the manufacture of common brick, 
and occurs in a superficial bed averaging 16 to 18 feet in thickness, 
underlain by fine sand. The clay is mined by steam shovel, and hauled to 
the ])lant in 6-yard cars by gasoline locomotives. Sixteen soft-mud ])ug 
mills and Potts presses are arranged in units of two machines each at 
such positions in the yard as to provide ample room for drying sheds 
l)laced so as to secure the mo.st economical trans])ortation of the brick 
from the presses, and to the kilns. The brick are dried in from 7 to 
10 days, depending upon the weather, and are fired in gas-fired field 
kilns. An 18-arch kiln will hold 756,000 brick, and a 30-arch kiln hold'" 



120 DIVISION OF MINES AND MINING 

1,250,000. Both sizes are in use, tlie choice depending on requirements 
at the time of setting. 

The total capacity of the yard is 650.000 brick per day. The company 
has jHirchased a townsite, and has built homes for renting at a nominal 
rate to its 650 employees. Recreational facilities are provided, and 
every attempt is made to secure a permanent force of satisfied 
employees. 

Sta7idard Bricl' Co. J. V. Simons, president ; R. G. Simons, vice 
president ; H. W. Simons, secretary. OtBce at 102 Stimson Building, 
129 West Third Street, Los Angeles. This company manufactures 
common red brick, and sewer brick, which are semi-vitrified common 
brick. Two yards are operated, one at Soto and Lugo streets, on the 
southern end of Boyle Heights, the other on Eucalyptus Street, in 
Ingle wood. 

Boyle Heights Plant : This property covers 8 acres. The material 
is a clay loam, 15 to 18 feet thick, underlain by sand. A steam shovel 
is used to mine the clay and load it into dump wayons, which are hauled 
to the di\y pans. The brick are made in Potts soft-mud brick machines, 
and are dried in air under sheds, requiring from three to four days. 
Three or four gas-fired field kilns are maintained, depending upon the 
demand. The brick in the arches are carried to the semi-vitrification 
point, Avith less than 10 /V absorption, are sorted out after firing, and 
sold as .sewer brick. The firing cycle is usually five and one-half days 
firing, and an equal time cooling. Mr. Welldon is foreman. 

Ingle\vood : At Inglewood the clay is of much the same character 
as at the Boyle Heights plant, containing lenses of sand and fine gravel, 
underlain by coarse gravel. The same brick-making ])rocess is used 
here as in the Los Angeles yard. Mr. Paye is foreman. 

Bibl : Cal. State Min. Bur. Prel. Kept. No. 7, p. 62. 

Torrance Bricl' Contpanij.^ T. H. Reed, president ; V. T. Pullman, 
secretary. Office address, Torrance. This company operates two jilants. 

Plant No. 1 : This plant is on the Plaza del Almo Boulevard, Tor- 
rance, and produces common red brick only. The property comprises 
15 acres, consisting of a 30-ft. bed of red and yellow plastic clay, over- 
lain by about one foot of soil. The clay is mined by scrapers, which 
deliver to a hopper in the ])lant. From the hopper, the clay is elevated 
by a bucket elevator to rolls. Tlie roll jiroduct is elevated by a bucket 
elevator to wire screens, which return oversize to the rolls for regrind- 
ing and deliver undersize to a pug-mill. Tlie pugged clay passes to an 
auger machine, ecpiipiied with a wire cutter. The capacity of the auger 
is 60,000 brick per day. 

The brick are transported to drying sheds' in hand-trucks. Four 
open field kilns, fired with natural gas. are in use. The kilns have a 
capacity of 750,000 brick each. The plant operates throughout the 
year. Electric ])ower is used, the installed capacity being 105 h.p. 
Thirty men are employed. 

Plant No. 2. This plant is at Graves Avenue and Jackson Street, 
^lonterey Park. Common brick, hollow tile, and red face brick are 

' Data supplied by W. B. Tiiokcr. cli.vtrict mining: engineer, December, 1927. 



(LAY RESOURCES AND CERAMIC INDUSTRY 121 

produced. The proi)erty consists of 20 acres of clay shale, from 20 to 
30 feet thick. Tlie ca))acity of the plant is 60,000 brick ])er day, or 
its equivalent in other ware. Electric power is used, the installed 
capacity bein^r 120 li.p. Forty men are employed. 

Tudor Art Tile Company. H. C. Hill, C. J. Biddle, T. P. Cook, and 
Geo. Skee, owners, deo. Skee, suj)erintendent. Office address, 1204 
Lane iIort<>a,ue Building, Los Anjieles. Plant at 5848.2 I^anta Pe Ave- 
nue, Los Antjeles. This company manufactures faience tile and inserts, 
usino- Alberhill clay. All special shapes are hand-molded in plaster 
molds, and an au<i'er machine is used for standai'd tile sha])es. Two 
yas-tired kilns are used. One is a rectangular semi-down-draft, 6-ft. by 
8-ft. by 6-ft., fired to cone 01 (1145° C.) for biscuiting, and the other 
is a rectangular muffle glost kiln, 5-ft. bv 6i-ft. bv 12-ft., fired to cone 
02 (1125° C). 

Clay-Worker rcj^orts' the organization of the Tudor Potteries, Inc., 
with a capitalization of $50,000, by C. J. Piddle and M. L. Vincent. 
No further information was available at the time of going- to press. 

The Vifrefrax Company.^ Harvey M. BroAvn, president; Geo. W. 
Clemson, vice president; C. V. Knemeyer, secretary; Ralph W. Brown, 
treasurer and general manager; Thomas S. Curtis, director of research. 
Office and plant at 5100 Pacific Boulevard, Los Angeles. 

This company manufactures a broad line of ceramic materials for 
the porcelain, white-ware, and electrical isulator trade, as well as super 
refractories in the form of prepared grains, cements and finished raw 
materials, together with a line of finished refractory brick and shapes 
for the glass industry. 

The company maintains an extensive research and development 
laboratory for fundamental investigations, as well as a control labora- 
tory for physical and chemical control of its regular products. 

In Imperial County, near Ogilby, California, the company owns and 
operates an immense deposit of cyanite, which forms the principal raw 
material for its mullite line of refractories and ceramic materials. In 
addition, the eomany has under long contract abundant su))idies of 
aluminum o.xide at ]\Iarysville, Utah; high alumina clays from the 
Alberhill and Santa ^largarita Ranch deposits; and contract control of 
what is believed to be the purest magnesium oxide resources in the 
United States. 

The mullite products of the company constitute its most important 
line. The material is manufactured in several grades, one of which is 
made esjiecially for the s})ark-plug iiulustry. The highest grade of 
mullite products, trade marked 'Durox, ' is manufactured by fusing a 
specially concentrated cyanite of great purity in the electric furnace at 
a temperature approximating 3000° C, whereby a yield of nearly pure 
mullite is obtained. 

The most important application of the mullite refractory material in 
its highest state of i)urity is in the form of glass-house refractories, in 
which form the company's product is gaining important recognition. 
Excellent service is being obtained in nmny conunercial installations 
on the Pacific coast, while an awakening interest in the east ha^- '^nn«pd 

' July. 1927, p. 58. 

- Copy prepared by the company. 



122 



DIVISION OF MIXES AND MINING 



orders to be placed by a number of prominent glass manufacturers 
within the past year. 

For the general refractories trade, for use in heavy-duty boiler 
refractories and the like, a cheaper grade of mullite is manufactured 
and sold under the trade mark 'California ]\Iullite.' This product 
readily competes in the eastern market with all other available sources, 
and has been pronounced after extensive tests to be equal to or the 
superior of any mullite available from the calcination of sillimanite. 
andalusite or cyanite. 

Illustrations of the plant are shown in photos Xo. 24 and 25. 

Bibl: Curtis, T. S., Super Kefractory Manufacture. Ceramic 
Industrv, Julv. 1926. 




Photo No. 25. 



CaUfornia MuUite brick being fired in tunnel kiln at Cone 28, 
Vitrefrax Co., Los Angeles. 



Washingfon Iron Worlds. Eighth and Mateo streets, Los Angeles. 
This company ojjcrates a sanitary ware enameling plant. The plant 
was visited, but in justice to the company no details are published, as 
other manufacturers of this ware refused publication of data. 

^¥estern Brick Co. G. A. Wild, president; J. J. Lagomarsino, 
superintendent. Office at Room 605, 126 AVest Third Street, Los 
Angeles. Tliis company manufactures common red brick only, using 
local clays. Plant No. 1 is at 1155 Lilac Terrace, on the southern side 
of Elysian Park. The cai)acity of this plant is 10,000,000 per year. 

Plant No. 2, is at Twenty-sixth and Colorado streets, Santa Monica, 
covering the same clay formation as th^t occurring on the property of 



CLAY RESOURCES AND CERAMIC INDUSTRY 



123 



r 

it 

i 



i 



I 
I 



\ 



ar. Either 
)ice of fuel 

t and ofifice 
I pottery is 
)oreelaiii is 
1 produced. 

272), hill 
, from the 
■vada china 

from San 

is piped to 
f the plant 
wo Harrop 
:. by 10-ft. 
glaze, and 
s the same, 
ns can be 
^'mperatnre 

ant on the 
thers being 
ic plant of 
d. 



e, and lies 
the south, 

uin Valley 

m the east. 

20 census). 

eons stone, 
iron, lead. 



section of 
er's Brick- 
ince about 



64. 



Marin County lies north of San Francisco, the Marin Peninsula and 
San Francisco Peninsula being separated by the Golden Gate. The 

'From Laizure, C. McK., Marin County: State Mineralogist's Report XXII, p. 314, 

X926, 



122 



DIVISION OF MINES AND MINING 



orders to be placed by a number of prominent glass manufacturers 
within the past j^ear. 

For the general refractories trade, for use in heavy-duty boilei" 
refractories and the like, a chea])er grade of mullite is manufactured 
and sold under the trade mark ' California Mullite. ' This product 
readily competes in the eastern market with all other available sources, 
and has been pronounced after extensive tests to be equal to or the 
superior of any mullite available from the calcination of sillimanite, 
andalusite or cyanite. 

Illustrations of the ])lant aro sliown in j)li()tos Xo. 24 and 25. 

Bibl : Curtis, T. 8., lSu])er Refractory Manufacture. Ceramic 
Industrv, Julv, 1926. 




Photo No. 25. 



California Mullite brick being fired in tunnel kiln at Cone 2S, 
Vitrefrax Co., Los Angeles. 



Washington Iron Worlis. Eighth and ]Mateo streets, Los Angeles. 
This company oi)erates a sanitary ware enameling plant. The plant 
was visited, but in justice to the company no details are published, as 
other manufacturers of this ware refused publication of data. 

Western Brick Co. G. A. Wild, president; J. J. Lagomarsiuo, 
superintendent. Office at Room 605, 126 West Third Street, Los 
Angeles. This company manufactures common red brick only, using 
local clays. Plant No. 1 is at 1155 Lilac Terrace, on the southern side 
of Elysian Park. The capacity of this plant is 10,000,000 per year. 

Plant No. 2, is at Twenty-sixth and Colorado streets, Santa Monica, 
covering the same clay formation as th^*^ occurring on the propertj^ of 




Photo No. 24. Interior view of iilant, Vltrefrax Company, Los Angeles. (Photo by courtesy of the coniiiany.) 
54970 — facing page 122 



122 



DIVISION OF MINES AND MINING 



within the p8 
For the g 
refractories { 
and sold un^ 
readily comp 
and has beei 
superior of { 
andalusite or 
Illustratioi 

Bibl: C 
Indiisl 






Photo No. 2! 



Washingto 
This compan 
was visited, 1 
other manuf £ 

Western 1 
superintende 

Angeles. Th ^ ^ . . _ 

local clays. Plant No. 1 is at 1155 Lilac Terrace, on the southern side 
of Elvsian Park. The capacity of this plant is 10,000,000 per year. 

Plant No. 2, is at Twenty-sixth and Colorado streets, Santa Monica, 
covering the same clay formation as th^t occurring on the property of 



CLAY RESOURCES AND CERAMIC INDUSTRY 123 

the Los Aiipfeles Pressed Brick Company and tlie Simons Brielc Com- 
pany. This plant has a capacity of 25,000,000 brick jjer year. p]ither 
oil or <?as fuel is used for firing in open field kilns, the choice of fuel 
depending upon relative economy at the time. 

Whiting-Mead Company. J. M. Bonner, secretary. Plant and office 
at 2260 E. Vernon Street, Los Angeles. The Whiting-Mead pottery is 
one of the largest on the Pacific coast in which sanitary porcelain is 
manufactured. A small quantity of garden i)ottery is also produced. 
The clays used are a white clay from Corona (No. 70, p. 272), hill 
blue (No. 9, ]). 287), and ])ink mollled (No. 7, ]). 328), from the 
Alberhill Coal and Clay Co., Englisli cliina and ball clays, Nevada china 
clay from near Cuprite, in addition to silica and feldspar from San 
Dieeo County. 

Tlie casting procecss is used exclusively. The clay sli]) is piped to 
all ])arts of the casting room, which is on the second floor of the plant 
building. Waste-heat driers are used. The ware is fired in two Harrop 
tunnel kilns, each 365 feet long, using trucks 5-ft. by 5-ft. by 10-ft. 
After the biscuit firing in the first kiln, the ware is dipped in glaze, and 
is glost in the second kiln. The firing cycle in the two kilns is the same, 
66 hours, so that the loading and unloading of the kilns can be 
synchronized. Precious metal thermocouples are used for temperature 
control in the kilns. 

The company also operates a .sanitary ware enameling plant on the 
same site. It is one of three such plants in California, the others being 
the Washington Iron Works of Los Angeles and the Pacific plant of 
the Standard Sanitary Manufacturing Company at Richmond. 

MADERA COUNTY. 
General Features. 

Madera County is in the east-central portion of the state, and lies 
between IMerced and Mariposa on the north and Fresno on the south, 
in a narrow strip, extending from the floor of the San Joaquin Valley 
on the west to tlie sunnnit of the Sierra Nevada iMountains on the east. 
Its area is 2112 square miles, and the population is 12,203 (1920 census). 
Granite is the principal mineral product. Some miscellaneous stone, 
gold and silver are also produced. Occurrences of copper, iron, lead, 
molybdenum, pumice, and building stone are known. 

Clay Resources. 

Common brick clay is reasonably abundant in the valley section of 
the county. The Sunset Brick Company (also known as Dyer's Brick- 
vard) operated at ]\Iadera for a time, but has been idle since about 
1919. 

Bibl : State Min. Bur. Bull. 38, p. 249 ; Prel. Kept. 7, p. 64. 

MARIN COUNTY. 
General Features.' 

Marin County lies north of San Francisco, the Marin Peninsula and 
San Francisco Peninsula being separated by the Golden Gate. The 

iFrom Laizure, C. McK., Marin County: State Mineralogist's Report XXII, p. 314, 
192(5. 



124 DIVISION OF MIXES AND MINING 

Pacific Ocean bounds it on the west, Sonoma County and portions of 
San Pablo and San Francisco bays surround it on the north and east. 
The total area of the countv is 529 square miles, and the ])oinilation is 
27,3-42 (1920 census). 

The main line of the Northwestern Pacific railroad runs throu^rh the 
eastern side of the county, and a narrow-<iauge branch traverses the 
western portion, passing through Point Reyes and continuing north- 
ward into Sonoma County. 

Marin County is for the most part rugged and picturesque, the 
ridges having steep sloi)es with only a few small flat valleys. The main 
ridge trends northwesterly, culminating at the south in Mount Tamal- 
pais, which overlooks both bay and ocean from an elevation of 2601 feet. 
From this main crest the drainage is both to the ocean and bay sides. 
Other notable topographic features are Tomales. Drakes, Bodega and 
Bolinas bays on the ocean side and Richardsons Bay on the inland side. 

Geology. 

The geology of the ]\Iarin Peninsula has been described by Lawson ^ 
and Osmont," to which the reader is referred for a detailed discussion. 

Geologically, the county is divided into two areas by the great San 
Andreas fault, which runs in a northwest direction from Bolinas Bay 
to Tomales Bay. The country lying east of the fault comprises about 
three-fourths of the county and is compo.sed almost entirely of Fran- 
ciscan rocks. These include massive sandstone, chert and intrusive 
bodies of serpentine and basalt. The Point Reyes Peninsula, which 
includes that portion of the county lying west of San Andreas fault, is 
composed mainly of Monterey shale, which is distinctly bituminous in 
places. Two small areas of volcanic rock are exposed near Inverness 
and Tomales Point. 

The mineralization of the county is diversified, but the deposits that 
may be classed as economic resources are limited, though important 
on account of their proximity to the metropolitan bay area. The eco- 
nomic minerals are mainly structural and industrial nonmetallic prod- 
ucts. Occurrences have also been noted of asi)haltum, petroleum, chro- 
mite, coal, jasper, garnets, manganese, mineral water, and natural gas. 
A little copper ore was at one time shipped, and traces of gold and 
silver have been found. Salt has been produced. 

Clay Resources. 

No deposits of high-grade clay have been reported in the county, but 
there is an adequate supply of clay and shale suitable for the manufac- 
ture of red structural ware at numerous places in the county. Common 
brick and other products have been produced since 1870 and three 
plants have been in operation at various times in the past. One plant 
is at present steadily producing, and a second plant is under construc- 
tion. 

McNear Brick Co. E. B. McNear, |)resident and manager; L. B. 
McNear, superintendent. ^Main office, 417 Berry Street. San Francisco. 
Manufacturers of connnon brick. 

The clay ])it and brick yard are at tidewater on ^McNear Point, four 
miles east of San Rafael. The present i)it is 3000 feet from the plant, 

' Lawson, A. C, San Fi-ancisco FoHo, No. 19:;, U. S. Geol. Survev. 
= Osmont, V. C, Bull. Dept. of Geology, Univ. of Calif., Vol. 4, No. 3. 



CLAY RESOURCES AXD CERAMIC IXDUSTRY 



125 



in a bank of sliale, slate, sandstone and clay in the face of a hill, under- 
lain by Franeiscan sandstone. The material sometimes re(|uires l)lastin<i\ 
It is deliveretl to a luadinji' hopper by two electi-ically operatetl tlraj;'- 
line scrapers operatino: on a lO/c slope in favor of the load. The clay 
bank has the form of an arc of a circle, with a radius of 300 yards, and 
a center at the loadinjr hoi)per. The unblasted bank stands at a heijjht 
of 'M) to (jO feet, and has a nearly vertical face. A view of the pit is 
shown on i)hoto No. 26. 

From the loading; hopper, the clay is loaded by a chain conveyor into 
2.") cu. yd. side-dump eonti'actoi-'s ears. Ti'ains of four ears each are 
hauled to the plant by a Jialdwin Westinghouse electric trolley loco- 
motive. 

At the plant, the clay is fed to two 9-ft., dry-])ans, elevated by a 
bucket elevator and delivered to a pu<>' mill and auger machine, e(iui])ped 
with a wire cutter. Drying is done under sheds, and reiiuires 15 days 
(average) in summer, and a longer time in winter. Firing is done in 




Photo No. 26. Clay and shale deposit of McNear Brick Company, showing 
loading hopper. Marin County. (From State Mineralogist's Report XXll, 
p. 318, 1927.) 

two Hoffman continuous kilns, fired with coal screenings or oil coke. 
The kiln turnover i)eriod is 15 days, and actual firing requires from five 
to .six days. The finishing temi)erature is 2000° F. 

The capacity of the plant is 60,000 common brick i)er day. From 45 
to 50 men are employed. 

Sample No. 198 was taken from the dry-pan feed. The superintend- 
ent stated that the sample was somewhat leaner than the normal feed 
to the plant as it had rained the previous night, and only the more 
sandy clay can be handled wlien the ground is wet. The test results 
are on page 329. Occasional seams containing calcite are encountered 
in the pit. These can be included in the mix if they are well distributed 
in the feed to the plant. 

Bibl : State Mineralogist's Reports VIII, p. 342 ; XII, p. 382 ; XIII, 
p. 615 ; XIV, p. 244 ; XXII, p. 317. Bull. No. 38, p. 249. Prel. 
Kept. No. 7, p. 64. 



126 DIVISION OF MINES AND MINING 

Louis Sharhori^ 554 Broadway, San Francisco, has recently (1926) 
leased tlie Keiiiillard j)i'opei-ty (see posi) and was exi)ected to begin 
the manufacture of floor tile dui-inu 1927. No further data are 
available. 

Earlier Kkports. 

The status of operations or clay deposits noted in previous reports- 
is as follows : 

Maillard Ranch. Lagunitas. Now owned by the Lagunitas Develop- 
ment Company, 833 Market Street, San Francisco. "Clay deposit on 
Spring Creek, about eight miles nortliAvest of San Kafael." Tlie deposit 
is still undeveloped, and is ])robably common clay. 

Patent Brick Companij. Galliiias Station. This ])lant has been dis- 
mantled, and the company is out of business. The liidecker Tile Co., 
Twenty-fourth and Union streets, Oakland (see under Alameda 
County), occasionally crushes some of the old brick from this place for 
use in the manufacture of roofing tile. 

RemiUard Brick (U)mpanij. Greenbrae. "Shale and sandstone, ])rac- 
tically inexhaustible." Tliis plant was dismantled about 1911. The 
company operates plants at Pleasanton, Alameda County, and at San 
Jose, Santa Clara County (9 v.). 

Bibl (On ]\Iarin Countv clav resources) : State ^Mineralogist 's 
Reports V, p. lOS ; VllI, p. 342; XI, p. 253; XII, pp. 329. 382; 
XIII, pp. 506, 615; XIV, pp. 24-1-248; XX 11. ])p. 317-319. Bull. 
38, p. 362 ; Prel. Kept. 7, p. 64. 

MENDOCINO COUNTY. 
General Features. 

Mendocino County joins Humboldt County on the south and is 
bounded by the Pacific Ocean on the west. Its area is 3453 square 
miles, and the population is 24,116 (1920 census). Lying in the Coast 
Range, the greater part of the county is mountainous and heavily tim- 
bered, except in the southeastern portion, through which flows the 
Russian River. Lumbering is an important industry. 

The rocks of the Coast Range within the limits of the county consist 
mainly of Franciscan (Jurassic), Chico (Upper Cretaceous), and 
various Tertiary sedimentary and metamorphic formations. The min- 
eral resources are largely undeveloped. Occurrences of asbestos, 
chromite, coal, copper, graphite, magnesite, and mineral water are 
known, as well as traces of gold, platinum, and silver. j\Iiscellaneous 
stone, coal and natural gas are produced in small amounts. 

Clay Resources. 

Common brick clays are available near the coast at the town of 
]\Iendocino, and also at Ukiah. Brickyards were at one time operated 
in these places, and at Talmage, near LHviah, but there has been no pro- 
duction in recent years. The brickyard of U. N. Briggs, at Ukiah, has 
been out of business since 1922. The most recent production of com- 
mon brick was at the Mendocino State Hospital, at Talmage. See below. 



' Laizure, op. cif., p. ?.19. 

= Especially in Prel. Rept. 7, p. 64. 



CLAY RESOURCES AND CERAMIC INDUSTRY 127 

Mendocino State Hospital. Talmaj^^e.' A brickyard was operated 
here for a few yeai's to iiiajuifai'turc l)riek for use in eonstruetion work 
at the liospital. The elay eousisted ol' a hx-al (lei)osit of gravelly silt, 
about 10 feet deep, and covering an ai'ea of al)out one-half acre. It 
was mined with a ])low and sci-aper. The plant is eciuipped with a 
disintegrator, conveyor, pug-mill, and auger machine, with a wire 
cutter. The lack of screening equipment reduced the capacity of the 
machinery to 8000 brick per day instead of 30,000, on account of gravel 
in the clay. Firing was done in open field kilns. The ])roduction cost 
of the brick was stated to be $11.50 per thousand. There has been no 
production since 1924, as it was found tiuit concrete construction is 
cheaper, with cement at $2.28 per barrel, delivered. 

l'>ibl: State Mineralogist's Kept. XIV. p. 415; State Min. Bur. 
Prel. Kept. 7. p. 04. 

MERCED COUNTY. 
General Features." 

^Merced County is situatetl lU'ar the geographical center of the state. 
It is bounded on the north by Stanislaus County, on the east by ]\Iari- 
posa, on the south by Madera and Fresno, on the west by Santa Clara 
and San Benito counties. It has an area of 1995 scjuare miles and sup- 
ports a population of 24,579 (1!)20 census), ^lost of the land is culti- 
vated, and much of it is irrigated, there being extensive irrigation 
systems covering the valh'y lands. ]\Ierced is essentially an agricultural 
county. 

The greater part of the county lies within the San Joacjuin Valley, 
and is comi)osed of unconsolidated sands, gravels, and clays of 
(^uateinary age. Along the eastern edge of the county there is a narrow 
belt of Tertiary formations, represented mainly by clays, shale and 
massive sandstone. On the western side of the county ('retaceous sand- 
stones and shales appear, and as the western boundary of the county, 
near the summit of the Coast Kange, is ap])roache(l, Franciscan rocks of 
•Jurassic age are exclusively in evidence. These consist mainly of 
slates, cherts, sandstones, schists, and serpentine. 

Both metallic and nonmetallic minerals have been found and pro- 
duced in Merced County. Among the former are gold, platinum, silver, 
cop])er, and a few ])ounds of lead. Crushed rock, gravel, sand, clay, 
and clay products are the chief nonmetallics. In addition to these the 
occurrence of a few other minerals has been noted, such as cinnabar 
(quicksilver), stibnite (antimony), barite, calcite, diatomaceous earth, 
magnesite, asbestos, manganese, coal, and soda niter, but for the most 
part these are entirely undeveloped and probably most of them do not 
occur in marketable quantities. 

Miscellaneous stone, including crushed rock, gravel, and sand, cement, 
brick and tile, are at the present time the principal mineral products. 
Structural materials of this nature will contribute almost exclusively 
to the future mineral output of the county. 

Clay Resources. 

No commercial deposits of high-grade clay have been found in the 
county, notwithstanding intensive investigations on the part of the 

' Information secured through the courtesy of Dr. Donald R. Smith. 
2 From Laizure, C. Mc-K.. Merced County: State Mineralogist's Report XXI. p. 
173, et seq., 1925. 



128 DIVISION OP MINES AND MINING 

I'alifornia Pottery romi)any and the Yosemite Portland Cement Com- 
pany. The hitter company recently built a cement plant near ]\Ierced 
and conducted an elaborate search for high-alumina clay, low in iron, 
but were finally forced to import this material from the lone district. 

There are a few remnants of the lone formation in the foothills of 
Merced County. These have not been thoroughly prospected, but there 
seems little reason to hope for commercial clay dejiosits in them. 

Clay suitable for the manufacture of common brick and hollow tile 
is available in the vicinity of Merced. A brickyard operated in Pierced 
from 1905 to 1910. The clays from various i)laces are now being used 
by the California Pottery Company (see post), the Yosemite Portland 
Cement Company, and the Craj'croft-Herold Brick Company of Fresno. 
The latter company mines clay from a deposit six miles south of Merced, 
and shii)s to its jilant in Fresno. 

California Pottery Co. F. A. Co.stello, president. General of^ce. 
Mills Building, San Francisco. Plant at Merced. The company also 
operates a plant in Oakland, Alameda County. The Merced plant is in 
the southern outskirts of Pierced, between the state highway and the 
Southern Pacific railroad. The ])roducts of the plant are roofing tile, 
hollow tile, and some 3-in. to 6-in. drain tile. Red, buif, and pink 
ruffled face brick were formerly made. 

The local clav is mixed with clav from the company's pit near Valley 
Springs, Calaveras County (samples Xo. 202-204. pp.' 299 and 337), and 
with red-burning clay from the Xatoma Clay Company in Sacramento 
C^ounty (.samples No. 210 and 212, p. 337). The local clay is a 
valley silt, and is mined to a depth of 10 feet with team and scrajier 
from a ])it adjoining the plant. It has in.sufficient bonding strength 
and plasticity to be used alone, and at least 359c of the Valley Si)rings 
clay, or an e(|uivalent amount of Natoma clay mu.st be mixed with it. 

The plant is equipped with a 10-ft. Raymond dry pan, one American 
number 290 auger machine for hollow tile and face brick, one American 
No. 233 auger for roofing tile, a 20-tunnel American waste-heat drier, 
and eight 30-ft., oil-fired, steam-atomized, round down-draft kilns. 
The dryer cycle is 36 hours. When there is insufficient dryer capacity, 
.some ware is dried on the drier floor. Each of the kilns has a capacity 
of 125 tons of hollow tile. 100 tons of Sierra roofing tile, or 90 tons of 
Spanish roofing tile. Firing requires 72 hours, to a maximum tempera- 
ture of cone 4—5 (1170° C.) for buff -colored ware, and to cone 2 
(1135° C.) for red-colored ware. Seventy-five per cent of the output 
of the plant during 1925 was roofing tile. The output of drain tile 
is very .small. 

The plant is handicapped by the fact that clay must be brought in 
from the north, and at the same time, the principal market for the 
])roducts are to the north. 

Forty -three men are emploj'ed. 

M. Goldman^ of Merced is the owner of large land holdings in the 
eastern ])art of the county, and it has been reported in the past that 
white clay, .suitable for the manufacture of pottery, occurs on this prop- 
erty in the vicinity of Merced Falls. The holdings have not been thor- 
oughly prospected, but the investigations that were made failed in find- 

^ Laizure, C. McK., op. cit., p. 179. 



CLAY RESOURCES AND CERAMIC INDUSTRY 1 29 

iii^' any liij^li-^'j'adc clay; llic malciial hriiii;- apparently a silt (h^jMtsit 
of iiKJcfinito coiiiposil ion, i-atli<M- tliaii a icsidual cla.w 

Clay (l('i)(>sits liav(> bocii i-t']»()i-1('(l from 'W o S., 11. 14 10. 'riicir char- 
acter and value have not been determined. 

J5ibl (Merced Countv clav resources) : State iMineralogist's 
Keports, XIV, p. 605; XXl, pp. 175, 177-179. Bull. 38, pp. 217, 
250; Prel. Kept. 7, p. 64. 

MONTEREY COUNTY. 
General Features.' 

Montere.y is one of the central coast counties, extending from the 
Pajaro River, MJiicli emi)ties into Monterey Bay, south to the sixth 
Standard ParaUel. It i.s bounded on the north by Santa Cruz County. 
San Benito, Fresno and Kings counties adjoin it on the east, and San 
Luis Obispo County bounds it on the south. Its area is 3330 square 
miles and its population 27,980 (1920 census). The main line of the 
Southern Pacific railroad, coast division, runs through the count}^ con- 
necting it with San Francisco and Los Angeles, as also does the state 
highway, a concrete paved road. Connecting county roads are kept in 
good condition, and it is only in the more remote mountainous sections 
that economic transportation becomes a problem. Tlie completion of 
the ])roposed road along the coast, connecting Monterey and San Luis 
Obispo, now open from the north to a point 18 miles beyond Big Sur 
and from the southern end as far norlli as Salmon Creek, will open up a 
lai'ge area which has heretofore been accessible only by water or steep 
trails, and one whose mineral resoui'ces are scarcely known. 

Among the principal topographic features is the great central Salinas 
Valley, the largest of the intermountain valleys of the coast region, 
being about 100 miles long by 6 to 10 miles in width, and lying parallel 
to th(> coast. P>etween the valley and the coast rises the Santa Lucia 
]Mou)itain Range, which culminates in a number of peaks, some reacliing 
nearly 6000 feet above sea level. Along the eastern side of the valley, 
and with their crests forming the eastern boundary of the county, are 
the Gavilan and Diablo ranges. Among the smaller valleys are the 
San Lorenzo, San Antojiio, Cholame, Carmel, and Nacimiento. In each 
of these the ])rincipal axis extends noi'tli westerly, parallel witli the 
general structure of the mountain ranges. 

Geology. 

The geology of most of Monterey County is described and ma])ped in 
Bulletin No. 69 of the State Mining Bureau, 'Petroleum Resources of 
California,' and the folio accompanying it. It is also shown in lesser 
detail on the Geological Maj) of California (1916). 

The Santa Lucia Range has a core of granitic rock. This is exposed 
in Santa Lucia Peak at an elevation of 5967 feet, and throughout the 
territory between Carmel River and Sur River, either along the coast 
or in the river cuts. Limestone and gneiss overlie the granite in places, 
and make up Pico Blanco, Ventana Cone, Marble Peak, Twin Peak, and 
Cone Peak. Most of the area from Mill Creek southward to Three Peaks 
and bounded on the northeast bj" Nacimiento River is made up of Fran- 

» Laizure, C. McK., Monterey County: State Mineralogist's Report XXI, p. 23, 1925. 
9 — 54979 



130 DIVISION OP MINES AND MINING 

ciscau sandstone and shale, witli intrusions of serpentine. It is in 
the region of these serpentine intrusions and the later intrusive 
acid dikes that tlie important mineral deposits of the Los l>urros 
district are found. The geology of tlie Los Burros district has been 
described in considerable detail by Ilill.^ There is evidence throughout 
of much faulting, and the precipitous coast follows a fault line. Monte- 
rey sandstone and conglomerate flank the mountains on the soutliwest 
side of Nacimiento River, and dip towards the valley. Most of the 
older sediments exposed east of the Nacimiento consist of Monterey 
shale, which is considerably folded east of Jolon. 

Along the coast, resting unconformabl}^ on the granite and Franciscan 
rocks, are raised beach deposits. The settlement of Gorda is located 
on the most recent of these terraces. This terrace is noticeable in 
Willow Creek, one-half mile back from its mouth, and also along the 
coast north of Gorda. These terraces are important in relation to placer 
gold. It is thought that the placer deposits near Jolon originated in a 
similar manner. 

In the northeastern part of the county, in the Gavilan Range, granite 
occurs associated with gneisses and schists. In places these rocks con- 
tact with massive beds of metamorphosed limestone, and dolomite is 
commonly associated with them. Feldspathic segregations give rise to 
commercial deposits of feldspar along the range as far south as the 
Pinnacles. In the vicinity of the Pinnacles there is a small area wdiere 
volcanic activity has taken place and extrusive volcanic rocks are in 
evidence. Farther south Tertiary sandstone and shales predominate. 
A long, narrow belt of the Franciscan rocks, including slates, sand- 
stones, and much schist and serpentine, extends from Priests Valley 
southeastward beyond Parkfield. AVorkable coal beds are exposed in 
the vicinity of Priests Valley and the principal quicksilver deposits 
occur in the Franciscan, not far from Parkfield. 

The following commercial minerals are of record as occurring in 
Monterey County: Arsenopyrite, barite, bitumen (asphaltnm), calcite 
(limestone and marble), ehromite, cinnabar (quicksilver), clay, coal, 
copper, diatomaceous earth, dolomite, galena, garnet, gold, graphite, 
gypsum, magnesite, magnetite, malachite, metacinnabarite, molybdenite, 
orthoclase (feldspar), psilomelane (manganese), quartz, salt, serpen- 
tine (asbestos), and stibnite. Not all of these have been produced in 
commercial quantities, however, nor is it known that all occur in suf^- 
cient quantity to be of value. About ten other species of miiieralogical 
interest only have also been noted. 

Clay Resources. 

No commercial deposits of high-grade clays have been discovered in 
the county. Common brick clays are not abundant, but there is little 
doubt that suitable deposits can be found if needed for local purposes. 
A clay pit and brickyard were at one time operated on a small scale at 
the south end of Salinas. The only clay-working operations in the 
county at present (1927) are two hand-made roofing tile plants, which 
are described below. 

Area Hoofing Tile Plant. Joe Area of Castroville owns and operates 
a small hand-made roofing-tile plant one mile east of Castroville on the 

1 Hill, J. M.. The Los Burros District, Monterey County, California : U. S. Geol. 
Survey Bull. No. 735-J, 1923. 



CLAY RESOURCES AND CERAI^tlC; INDUSTRY lol 

Salinas road. The property covers one acre. The clay deposit consists 
of 18 ft. of yellow plastic clay, underlying one foot or less of black 
adobe. See sample No. 117, ])age ;i24, for test data on the clay. Tlie clay 
is mined ])y hand and is fed to a horse-driven ]ing-mill. After the 
l)uyged clay is aged for a few days, the tile arc shaped by hand over 
wooden forms, and are then dried in air under sheds. The clay is 
excessively plastic, and in the cool moist climate of the region, drying 
is very slow. The tile are fired in an oil-fired rectangular u])-draft kiln. 
The capacity of the plant is 500 tile per day, and three or four men 
are employed. 

Mr. Area reports that good roofing tile clay occurs on the Martin 
ranch near the Carmel mission. It was u.sed by the Indians in making 
roofing tile for the IMission. ]\Ir. Area attempted to establish his plant 
there but found that the land was too valuable. 

Monterey Mission Tile Co. II. L. Watson, i)resident; T. II. Bane, 
secretary treasurer. The new plant of the jMonterc}- ]\Iission Tile Com- 
pany is near Seaside, and about two miles north of Del Monte. The 
property covers thi-ee acres. The products are red-burned roof tile, 
floor tile, and step tile, all of which are hand-made. The clay is mined 
by hand methods from the Thomas Field ranch on the Laguna Seco 
grant, at a point 5.5 miles toward Salinas from the junction of the 
Salinas road and the Santa Cruz road just north of Del IMonte. The 
total haul to the plant is seven miles. The clay is a black adobe, 10 
feet deep, covered with 2 feet of sandy soil. Sample No. 214 was taken 
from the clay in storage at the plant. See page 327. 

At the plant, the clay is mixed with approximately 20% of grog con- 
sisting of ground rejects from the kiln, pugged in a Patterson vertical 
pug-mill, and aged for at least three days before molding. A 5-hp. 
motor drives the grog crusher and the pug mill. 

The tile are shaped by hand with Mexican labor, and are dried under 
sheds. The drying time varies widely Avith climatic conditions, but 
usually requires at least two Aveeks, on account of the cool, humid 
atmosphere generall.v prevailing in this region. 

The tile are fired in a cylindrical up-draft kiln, 13^ feet in diameter 
in the lower 6-ft. section, tapering to six feet in diameter in the upper 
5-ft. section, and finally tapering to four feet in diameter at the throat. 
The kiln will hold ai)iU'oxinuitely (iOO roofing tile. Tt is fired with four 
oil burners, placed in pairs at opposite sides of the kiln. The oil is 
preheated to 120° F. in electric heaters placed in the pipe line, and is 
atomized with air from motor-driven blowers. Four base-metal thermo- 
couplos. with a multiple rccordci-, are used to control the firing, in addi- 
tion to Orton standard cones. The niaxinnnn temperatures recorded at 
the end of firing are 1830° F. on the bottom, and 1470° F. on the top 
of the kiln. Firing requires 32 to 38 hours. 

The product is distinctly different in appearance from machine-made 
tile, and from most of the hand-made tile produced in the state, on 
account of the irregular texture and the play of colors to be seen on 
each individual tile. The owners of the plant were formerly builders 
in the district, and the tile plant is the outgrowth of a local desire for 
more artistic effects than could be obtained with the tile previously on 
the market. Since the tile are made by an expensive process, they are 



132 DIVISION OF MINES AND MINING 

only to be seen on some of the finest residences in Carmel and Pebble 
Beach. 

From 8 to 10 men are emploj'cd when the plant is in fnll operation. 

Bibl: State Mineralogist's Report XXI, p. 57, Jan. 1925. 

Miscellaneous Deposits. 

Echstine Deposit. Mrs. G. P. Echstine, Pleyto. In T. 24 S., R. 8 E., 
M. D. M. An ocenrrence of white plastic clay had been reported to the 
Burean. The deposit was investigated in September, 1926, and was 
found to consist of a plastic clay that is graj'ish white when dry, but 
darkens considerably when wet, and fires to a red color. The property 
is difficult of access, and is some 18 miles from the railroad, hence the 
clay has no possible commercial value. 

Heins Lal-e Deposit. Owner, Martha E. Bardin, Salinas. Tlie bot- 
tom of Heins Lake, now dry, situated about two miles southeast of 
Salinas, is reported to be composed of blue clay. There is about 300 
acres in the deposit, and it is said to average four feet in depth. ^ No 
investigation was made by the author. 

Jens Deposit. Chualar. A supposed deposit of clay from wliieli it 
was reported that several thousand tons had been shii)pe(l. An investi- 
gation showed that the material is low-grade feldspar. 

Bibl (Clav resources of Monterey County) : Cal. State Min. Bur. 
Bull. 38, p. 250; Prel. Kept. 7, "p. 65; Kept. XXI, pp. 29 and 57. 



NAPA COUNTY. 



General Features. 



Xapa County, witli a hind area of 783 square miles, runs nearly to a 
point at both extremities. It is bounded on the east by Solano and 
Yolo counties and on the west by Lake and Sonoma counties. Its 
southerly end touches San Francisco Bay. The main drainage system 
of the county is that of the Napa Valley, which is a rich agricultural 
section, and is served by a branch line of the Southern Pacific railroad, 
extending from San Francisco Bay to Calistoga, in the northwestern 
corner of the county. Mt. St. Helena, a prominent landmark, is in the 
northwest corner, at the junction with Lake and Sonoma counties. 

The principal geological formations in the county, in addition to 
Recent sediments in the valleys, are Franciscan (Jurassic) slates, sand- 
stones and serpentine, Miocene sandstones and shales, and Tertiary 
voloanics.- 

The in-incipal mineral resources include quicksilver, inineral water, 
miscellaneous stone, and magnesite. Occurrences of diatomite, lime- 
stone, copper, iron, chromite, gold, silver, and mineral paint have been 
noted. A cement i)lant at one time operated at Napa Junction. 

Clay Resources. 

Common clays .suitable for brick manufacture occur in the Napa 
Valley. Previous to 1890 there was a plant in operation near Napa, 

1 Laizure. C. McK., op. cit., p. 29. 

- Smith, J. P., The geological formations of California : Cal. State Min. Bur. Bull. 
72, and Geological Map. 



CLAY RESOURCES AND CERAMIC INDUSTRY 



133 



where brick and drain tile were made. The cement plant at Napa 
Jnnction used local clay in cement manufacture. 

An interesting occurrence oi" kaolin is described at considerable length 
below, not so much for its present value, which is doubtful in the pres- 
ent state of development, but because of its significance in encouraging 
further prospecting for commercial deposits in tliis 



region. 



Clark and Mai\'ih Kaolin Mine. This property, referred to in a 
previous report ^ as a 'china clay' deposit, owned by W. R. Teale, has 
been acquired by J. R. Clark and C. L. Marsh of Calistoga. The 
propertv includes the following areas: S.^?, SEj, Sec. 12, and Ni NE^, 
Sec. 13," T. 8 N., R. 7 W.. and the Si SW], Sec. 7, NW^ NWj, Sec. 18, 
and the diagonal (NW.-SE.) NEJ 5sE\ NW-1 Sec. 18, in T. 8 N., R. 6 
W., M. D. M., a total of 300 acres. The principal workings lie near 
the top of a hill, 3.5 miles by road south of Calistoga. Some road grad- 
ing is necessarv before trucks can be run to the mine. 




Photo No. 27. Clark and Marsh Kaolin Mine. Main workings, facing west. 
Note scrub brush over deposit, and timber in left background on other 
formations. Calistoga, Napa County. 

The deposit is a residual kaolin formed by the alteration of a rhyolitic 
rock that has a wide distribution in the region. This rock forms the 
crest of certain of the low hills south of Calistoga, and is distinguishable 
by its white color, and its hardness at the surface, where silicification 
has taken place. The debris covering the formation is very thin, and 
is composed of irregular grains and fragments of the silicified rock 
itself, with only enough soil to support a scattering growth of shrubs, 
principally manzanita, w^hereas the soil resulting from the decomposi- 
tion of most of the other formations in the region is adequate to support 
a growth of hea^7- brush and trees. This characteristic is illustrated 
in photo No. 27, wliicli is a view of tlie main workings. 

Plate VII is a sketch map of the main workings, from which over 200 
tons of kaolin have been removed, some of which has been shipped to 

'Cal. State Min. Bur. Prel. Kept. No. 7, p. 65, 1920. 



134 



DIVISION OP MINES AND MINING 



various clay products manufacturers for testing. An examination of 
the -workings shows that the progress of kaolinization has been very 
erratic. The hard, silicified zone at the surface is from one to three 
feet thick. Below this, the kaolin varies from a non-plastic aggregate 
of partly-altered feldspathic grains, to a fine-grained mass that has 
fair plasticity. In places, following lines of fracture, the kaolin is 
heavily stained bj' iron-bearing minerals, but between these discolored 
areas, the mass of the material is practically w'hite in color. The most 
discouraging feature of the workings is that most of the headings end 
in material that is badly iron-stained. It is estimated that 20% of the 
material exposed in the underground workings is contaminated with 
iron. The iron-stained portions are distributed in such a manner as 



Plate VII 





^/KETCH MAP 

or 

CLAR/K-^'^'^ MARSH KAOL/N M/NE 

CAL.'STOOA, CAL/F. 



5<r» L. £• 

to 



ZO Ft 



Uj 



to make hand-sorting necessary, rather than selective mining, if the 
material is to be mined on a commercial scale. The writer believes 
that the general conditions are sufficiently favorable to warrant more 
extensive prospecting near these workings, especially at greater depths 
below the surface. 

From a point alongside a road about 1500 ft. north of the main 
workings, and at an elevation 400 feet below them, is a 72-ft. tunnel, 
having a direction of S. 75° W. Most of the material encountered in 
the tunnel is well kaolinized. but the mass of the material is slightly 
stained with iron. The best kaolin lies near the floor of the tunnel, in 
that portion between 25 and 50 feet from the portal. Nearer the face, 
the rock is not so well decomposed, and there is a large proportion of 
unaltered quartz and feldspar. It is possible that an extensive deposit 
of kaolin may be ^ou»d b}^ farther prospecting in this locality. No 



CLAY RESOURCES AND CERAMIC INDUSTRY 185 

streaks of heavily iron-stained material were found in the tunnel, as in 
the workings near the top of tlie hill. 

This deposit of kaolin has attracted considerable attention in the past 
from various clay products manufacturers, but none have felt war- 
ranted in incurring the expense of leasing or purchasing the property, 
and doing a sufficient amount of prospecting on it to determine the 
limits of workable material. It is one of the few localities in the state 
where high-grade residual kaolin has been found, and it is more accessi- 
ble to marketing centers than the El Cajon IMountain deposit in San 
Diego County oi- the deposits at Ilart, San Bernardino County, or 
even tlie sedimentary deposit on the Hunter Raneli, Orange County. 

Sample No. 190 is representative of the average of the white kaolin 
exposed in the main workings. Sample No. 191 is from the same 
workings, but was taken from the iron-stained portions of the exposures. 
Sample No. 192 was taken as representative of the average white kaolin 
from the lower tunnel. The test results are on ])ages 261, 280 and 281. 

Bibl (Clay resources of Napa Countv) : State Min. Bur. Rept. 
XIV, p. 262 ; Prel. Kept. 7, p. 65. 

NEVADA COUNTY. 
General Features. 

Nevada County is 12 to 20 miles wide and 80 miles long, reacliing 
from the Sacramento Valley to the Nevada line. It is bounded on the 
north by Yuba and Sierra counties, on the east by the state of Nevada, 
on tlie south by Placer, and on the west by Yuba County. It contains 
974 square miles, and its population is 10,860 (1920 census). 

The mineral production of the county is mostly gold and silver. 
Some chromite, copper, granite, lead, and miscellaneous stone are also 
produced. Antimony, asbestos, barytes, clay, gems, iron, mineral paint, 
IXvrite, soapstone, and tungsten also occur in the county. 

Clay Resources. 

Previous publications of the Bureau ^ have reported several clay 
deposits from the vicinity of Grass Valley, Nevada City and Colfax. 
Most of the localities mentioned and a few others that have been recently 
called to the attention of the Bureau were visited, but in no place was 
found a deposit of high-grade clay that would warrant exploitation 
under any commercial conditions that are likely to prevail for many 
years to come, although in a number of localities common brick clay of 
inferior quality occurs and in at least one locality, on the Sonntag 
Ranch, near Peardale (sample No. 169), a buff -burning clay with low 
shrinkage and fair strength was found. 

The geology of this region has been described by Lindgren and 
others.- The few deposits of clay-like materials occur in the Tertiary 
superjacent series of sedimentary rocks and rhyolitic flows, and in 
many places are closely associated with the Neocene gold-bearing 

' Prel. Rept. No. 7, p. 6a. 

= Lindgren. Waldemar, The Oold Quartz Veins of Nevada City and Grass Valley, 
California; Seventeenth Ann. Rept. U. S. Geol. Survey, Part 2, pp. 1-262, 1896. 

Lindgren, "Waldemar, Tertiary Gravels of the Sierra Nevada of California : Prof. 
Paper 7.3, U. S. Geol. Survev, pp. 121. 159, 1911. 

MacBovle, Errol. Mines and Mineral Resources of Nevada County: State Miner- 
alogist's Report XVI, Dec, 1918. 



136 DIVISION OF MINES AND MINING 

gravels. One of the most typical of these occurrences is the altered 
rhyolitic tuff (sample No. 172) in the Manzanita gravel pit, northeast 
of Nevada City. This is commonly described as 'pipe clay.' It is 
nearly white in color in tlie dry state, has good plasticity, but burns 
red and has a high drying and firing shrinkage. Other clays sampled 
in this region i)robably are variations of the same material, but mixed 
with varying proportions of decomposed granite and other products of 
decomposition of the bedrock series. In general, the better grade of 
clays differ from those found in Placer County from Alt a to Gorge 
(page 158) in that they have a workable plasticity and workable firing 
properties, whereas all of the volcanic claj's of Placer County thus far 
examined seem to be totally unsuited for ceramic uses. 

The only known clay occurrence of possbile commercial interest in 
the county is that at Pine Hill, described below under Pine Hill Mine, 
and John Sweet Kaolin Deposit. 

Banner Mountnin. Sample No. 170: This was taken from near the 
Banner Mountain road, 1.0 mile east from the intersection with the 
Nevada City-Colfax road, in or near the NWi NE^, Sec. 30, T. 16 N., 
R. 9 E., M. D. M. This probably corresponds to the deposit formerly 
rei)orted under the name of E. M. Taylor.^ The present owner of the 
adjoining property is W. E. Parsons, of Grass Valley. No develop- 
ment work has been done, but the deposit can be traced for several 
hundred feet, and is at least six feet thick, overlain by red andesitic 
soil. The material is a white clay shale, and the sample probably con- 
tains more iron than would be expected in the mass of the deposit, away 
from surface contamination. The test results are on i)age 315. 

Beaser Ranch, Chicago Park. Sample No. 168: The sample Avas 
taken from an undeveloped deposit on the P. ]M. Beaser Ranch in the 
Si Si SWi, Sec. 15, T. 15 N., R. 9 E., M. D. M. The clay is exposed 
along the side of a small creek bed. The extent of the deposit could 
not be determined, but it is at least two to three feet in thickness, and 
is overlain by nonplastic rhyolitic tuff. The deposit is within one-half 
mile of the narrow gage railroad connecting Colfax with Grass Valley. 
The test results are on page 313. 

Manzanita Mine. Sample No. 172: This is a sample of 'i)ipe clay' 
from the Manzanita gravel pit, in the NE^ SW|, Sec. 6, T. 16 N., 
R. 9 E., M. D. M., 1.5 miles on the North Bloomfield road from the 
center of Nevada City. The clay occurs in beds from 3 to 6 ft. thick, 
interbedded with rhyolitic sandstone beds of approximately the same 
thickness. The total thickness of rhyolitic clay and interbedded sand- 
stone is approximately 90 feet. This formation is overlain by 150 feet 
of andesitic tuffaceous breccia, and is underlain by 190 ft. of Neocene 
gold-bearing gravel, which in turn rests on the granodiorite bedrock. 
This occurrence and that represented by sample No. 171 probably 
corresponds to the occurrence previously described as lying in Sec. 6, 
T. 16 N., R. 9 E., near the Reddik and'Odin mines.- The test results 
are on page 342. 

North Bloomfield Road. Sample No. 171: This sample was taken 
from alongside the North Bloomfield Road, 1.8 mile northeast from 

' Cal. state Min. Bur. Prel. Kept. No. 7, p. 65. 
= Op. cit. 



CLAY RESOURCES AND CERAMIC INDUSTRY 137 

Nevada City, in tlie Wi Sec. 6. T. 16 N., R. 9 E., M. D. M. The 
ownership was not determined. Alonp; the upper side of the road at 
this point is an exposure of moderately plastic, fine-ofrained clay, nearly 
white when dry, but <»reenish when Avet. The bed is over 10 ft. thick 
and can be readily traced for over 300 feet. It is overlain by decom- 
jtosed andesite. The test results are on pa«:e 329. 

The Pi7}€ Hill Mine, now controlled by Tra J. Coe, 462 Mills Buildinp:, 
San Francisco, is on the northern half of Pine Hill in Sec. 13, T. 14 N., 
R. 7 E., M. D. M., one mile north of Wolf Post Office, and nine miles 
by road to a proposed railroad siding near Auburn. About two-thirds 
of this distance is on a paved highway. The property comprises 160 
acres, including three patented claims, the Golden Gate, Golden Gate 
Extension, and Thrasher. 

The mine was originally located and developed as a copper and gold 
prospect.^ 

Several well-defined veins have been found on the property. These 
contain some gold, silver, and copper, associated with quartz, pyrite, 
and limonite. The footwall of the principal vein is diabase, and the 
hanging wall is serpentine. Khyolite and iron-stained porphyry are 
found in places. The rocks in the vicinity of the veins have been 
altered, and considerable kaolin has been formed, some of which is 
moderately pure. Pour sami)les were taken from various points in the 
underground workings. 



o* 



Sample No. 159: This is a sample of nearly white kaolin that occurs 
as a gouge in a vein exposed by workings on the west side of Pine Hill, 
near its crest. At this point, a cross-cut tunnel, 50 feet long, was run 
to cut the vein. From near the end of the tunnel, a vertical Avinze, 
26 feet deep, was sunk', which was continued as an inclined winze in 
the vein which has a dip of 31°, S. 35° E. The inclined winze is now 
filled with water and debris to within 60 feet of the bottom of the verti- 
cal winze, so that the total depth of the incline could not be determined. 
The material included in the samiile was from the footwall gouge that 
is expo.sed in the incline throughout its accessible length. It was 
impossible to secure a sample entirely free from iron staining by infil- 
tration from the overlying pyritic quartz, as the workings have been 
open for many years, and are usually flooded to the floor of the tunnel 
each winter. It is claimed that auger holes have been drilled into the 
footwall to a depth of 14 ft. without penetrating the kaolin, and that 
below the layer of surface contamination, the kaolin is nniformly Avhite 
in color. It was not possible to verify this statement. No such thick- 
ness is exposed in the cross-cut. It is obvious that if the drill-holes 
had not been drilled at right angles to the dip of the vein, false indica- 
tions of thickness would have resulted. Further exploration in these 
workings is necessary before any attempt can be made to predict the 
quantity and quality of kaolin that may be available. The test results, 
page 261, are favorable, but not as satisfactory as to color as in sample 
No. 160. 

Sample No. 160: This is a sample from the lower 10 feet of a 50-ft. 
vertical shaft near the top of the hill, 200 yards or more east of the 

1 MacBoyle, Errol, Mines and Mineral Resources of Nevada County : State Miner- 
alogist's Report XVI, 1921. 



138 DIVISION OP MINES AND MINING 

West tunnel. The fired color and other ceramic properties of this 
material are satisfactory^ for man.y high-grade uses, as shown on 
page 261, and the occurrence of the deposit is such as to warrant the 
prediction that a commercial tonnage of uniform material would be 
disclosed by farther development. The material cut by the first 40 ft. 
of the shaft is similar in ]ihysical properties and in mineralogical con- 
stitution, but is light pink and yellowish in dry color, showing the 
presence of a higher proportion of iron oxide. 

Sample No. 166: This is a picked sam])le of wliite kaolin, occurring 
as a gouge in a vein cut by a tunnel entering the North side of the hill, 
at a low level. The gouge is from two to four feet thick, and grades 
into altered country rock, similar in composition to sample No. 167. 
The continuity and homogeniety of this occurrence is doubtful. It is 
unlikely that this occurrence will be of importance, as continuity, 
homogeneity, and sufficient thickness for economic mining may be 
lacking. The test results are given on page 316. The fired color is 
not as good as in sample No. 160, and the fusion point is considerably 
less. 

Sample No. 167 : This is a composite sample from a cross-cut branch 
of the East tunnel. It is typical of the altered country rock of the 
hill, and occurs in abundance. The test results are given on page 315. 
It has weak plasticity. 

Bibl: State Mineralogist's Report XVI, Nevada County, p. S8. 

Sonntag Fanrh, PeardaJr. Smnple No. 169: The samjile was taken 
from a drainage ditch on the south side of the You Bet road, 1.8 mile 
from Peardale station on the narrow gage railroad. The adjoining 
propertv to tlie south is o-waied by H. E. Sonntag, and is in the NE^, 
Sec. 3, T. 15 N., R. 9 E., M. D. M. At this point a bed of white plastic 
clay crosses the road in an east-west direction, but is difficult to trace 
because of the overlying andesitic debris, which weathers to a red, 
plastic soil and obscures the underlying structure. No development 
work has been done. The clay bed is at least 4 feet thick. The sample 
was taken by digging a hole about one foot deep in order to avoid 
contamination from the andesite soil that has been washed over the out- 
crop, but even with this precaution, the sample contains more iron- 
bearing minerals than would be found in the mass of the deposit. 
Mr. Sonntag reports that the same clay was found in a spring on his 
ranch ^ mile to the west, but this could not be verified. It is not certain 
whether this deposit, or the one from which sample No. 168 was secured,^ 
is the one referred to in previous reports^ as occurring on the De Golia 
Ranch. The test results are on page 313. 

John Sweet Kaolin Deposit. John Sweet of Wolf owns the south 
half of Pine Hill, consisting of 120 acres in Sec. 13, T. 14 N., R. 7 E., 
M. D. M. The same formations as those described under 'Pine Hill 
Mine' persist on this property, but very little development has been 
done. A 30-ft. vertical sliaft has been sunk on the N^ NE^ of the 
section, but this was not accessible at the time of visit in August, 1925. 
The general appearance of the material in the dump at this shaft 

• See under Beaser Ranch, ante. 

»Cal. State Min. Bur. Prel. Kept. No. 7, p. 65, 



CLAY RESOURCES AND CERAMIC INDUSTRY 139 

resembles that exposed in the 50-ft. vertical shaft on the Pine Hill 
property, from which sample No. 160 was taken, and the rather meager 
evidence available points to the conclusion that the kaolin was formed 
by the alteration of a diabase. A small sample. No. 158, was taken of 
the material lying on the dump, but was not tested. 

An unsuccessful search was made for the deposits previously 
described at Union Hill, and that in Sec. 29, T. 17 N., R. 9 E., M. D. M. 

Bibl (Clav resources of Nevada County) : Cal. State Min. Bur. 
Bull 38,' pp. 217-218, 250-251; Prel. Kept. No. 7, pp. 65-66. 

ORANGE COUNTY. 
General Features.' 

Orange County is bounded on the east by Riverside County, north by 
San Bernardino and Los Angeles counties, west by Los Angeles County 
and the Pacific Ocean, and on the soutli by San Diego County. It com- 
prises 795 square miles, about three-fifths of this area being valley land 
and the remaining two-fiftlis mountainous and foothill land. The popu- 
lation of tlie county is 61,375 (1920 census). 

The Santa Ana Range of mountains is the line between Orange and 
San Bernardino counties, at the northeast corner of the former county. 
It is also the dividing line between Orange and San Diego and Riverside 
counties. This range also sends up a line of foothills westwardly along 
the seashore nearly half way across the county. All the western por- 
tion of the county is included in the Santa Ana Valley. The highest 
point of land has an elevation of 5675 feet above sea level, and is known 
as Santa Ana Peak. 

The Santa Ana River comes into the county near the northeast corner 
and continues through it in a northwesterly direction, flowing into New- 
port Bay. Santiago Creek has its rise in the Santa Ana Range of 
mountains, and flows in a northerly and westerly direction, emptying 
into the Santa Ana River about two miles northwest of the city of 
Santa Ana. Aliso Creek has its rise in the same range, but on the 
southern slope of the mountains, and runs in a southwesterly direction, 
flowing into the ocean near Arch Beach, about twenty miles southeast of 
the mouth of the Santa Ana River. Trabuco, Mission Vie jo, and San 
Juan creeks have their rise on the south side of the Santa Ana Range 
and come together near the sea, reaching the ocean at 'San Juan-by-the- 
Sea.' Coyote Creek marks the boundary of the county on the west. 

Geology. 

The formations of the region consist of a base of granitic and 
metamorphic rocks overlain by Cretaceous, Tertiary, and Pleistocene 
sediments. 

The main portion of the Santa Ana Mountains is composed of ancient 
crystalline rocks, mostly slates of Jurassic age ; along the western and 
southern flanks, rocks of Chico age are exposed, which in turn are over- 
lain by small patches of the Eocene. In the Laguna Hills the formations 
exposed are mainly coarse sandstone of Eocene age. These are overlain 
along the edges of the hills by beds of sandstone and sh^le of the Mon- 
terey series. In the flat area running from Tustin to El Toro the dia- 



1 Tucker, Vi". B., Orange County: State Mineralogist's Report XXI, pp. 58-59, 1925. 



140 DIVISION OF MINES AND MINING 

tomaeeous shale of the IMonterey series is present, occupying a synclinal 
ti-ouuii between the Santa Ana ^Mountains and the Lagnna Hills. This 
condition continues southeast through the Capistrano district to the 
San Diego County line. 

For detailed geology of Orange County the reader is referred to the 
reports by Bowers ^ and Fairbanks- in two of the earlier State 
^Mineralogist's Reports. 

Orange County is among the upper three counties in California in 
the value of its mineral production, the other two being Los Angeles 
(first in 1926) and Kern (second in 1926) counties. In all three cases, 
the principal product is petroleum. Of secondary importance in Orange 
County are natural gas, miscellaneous stone, clay, brick, gold, silver, 
copper, lead, and zinc. Besides these substances, occurrences of coal, 
gypsum, diatomite, sandstone, and tourmaline have been found in 
Orange County. 

Clay Resources. 

Low-grade clays for use in making red-burned structural ware are 
fairly abundant in the county, and plants seeking a location need have 
no difficulty in finding suitable material. 

On the w^est side of the Santa Ana Range are deposits of high-grade 
clay that are apparently equal in geological age to the Eocene clays of 
the Temescal Valley (Alberhill-Corona district) in Riverside County. 
These deposits have been developed in recent years, and a number of 
exceptionally good varieties of fireclay are now being produced com- 
mercially. An especially interesting occurrence of flint fireclay occurs 
on the Goat Ranch, in Santa Ana Canyon, in the Upper Chico (Upper 
Cretaceous) formation. 

American Silica Company. G. Ray Boggs, president. Office, Suite 
1212 Pacific Mutual Building, Los Angeles. This company controls 
an important deposit of fireclay on the Hunter and Robinson ranches, 
12 miles by road east of the town of El Toro. The Hunter Ranch lies 
in Sec. 11,'t. 6 S., R. 7 W., S. B. M., and the Robinson Ranch is adjoin- 
ing. At the time the property was visited, in August, 1925, some 1500 
tons of clay had been mined from two different openings. Two samples 
were taken, No. 63 and 64. The test results are on ]iage 260. Since 
1925, the property has been extensively developed, and new deposits of 
valuable fireclays have been discovered, hence a description of the 
earlier developments is of little value at this time. Through the cour- 
tesy of Mr. Boggs, several samples of the clay that was in use in 1926 
were secured, both as crude clay, and in mixes that were ]irepared for 
the manufacture of fire brick. See samples No. 266, 268 and 270, on 
liages 292. 260 and 282. respectively. 

The clays are probably of Eocene age. 

Brea Clay Products Company. C. M. Haaker, president; A. D. 
Yost, superintendent. Home office, Brea. The plant is on the eastern 
side of the town of Brea. 

Operations commenced in the summer of 1925. Common red brick 
is manufactured fro]ii local surface clay which is mined to a depth of 

^Bowers, Stephen, Orange County : State Mineralogist's Report X, pp. 399-409, 
1890. 

= Fairbanks, H. W., Geology of San Diego County : also portions of Orange and 
San Bernardino counties: State Mineralogist's Report XI, pp. 113-118, 1893. 



1 



CLAY RESOURCES AND CERAMIC INDUSTRY 141 

10 to 12 feet with a steam shovel. A drag-line eonveyor delivers tlie 
elay to a belt eonveyor Avhieh feeds a png-iiiill and aiifjer machine, 
equipped with a hand operated side cutter. After drying; in the open 
and under sheds, the brick are fired in open oil-fired field kilns. A 
semi-Diesel engine is used for operating the i)lant. 

The output at the time of visit in July, 1925, was 60,000 brick per 
day, and an increase to 80,000 was expected within a short time. The 
company also expected to i)roduce hollow tile and roofing tile. 

lSam])h> Xo. 6;") was taken for testing. See page 322. 

Garhn- Brick and Tile Co. II. Garber, president, Olive. The com- 
pany controls 6 acres, one-half mile east of Olive, on the Orange County 
Park road. Common brick, hand-made roofing tile, floor tile, roof 
dressing and a dust product for molding sand are manufactured. 

All of the clay used is mined from a pit on the property. Material 
is transported from the clay pit by a drag scraper to the plant, where 
it passes through rolls, is elevated to storage bins. The brick are made 
by the soft mud process. A pug-mill prepares the clay for the brick 
press as well as for the tile plant. The brick are conveyed by a cable 
convej-or to drying racks. After drj'ing, the brick are burned in field 
kilns, using natural gas as fuel. 

Both roof and floor tile are hand molded, air dried under sheds, and 
fired in two down-draft kilns. The rated output of the plant is 2000 
roof tile and 25,000 brick per day. The ecpiipment includes a 30-h.p. 
boiler, Ingersoll-Rand compressor, Blake type crusher, screens and 
elevators. From 25 to 30 men are employed. 

Bibl: State Mineralogist's Report XXI, p. 65. 

Gladding, McBean and Company. Office of Southern Division at 
621 South Hope Street, Los Angeles. This company, through its merger 
with the Los Angeles Pressed Brick Com))any, now owns the Goat 
Ranch, noted in previous reports^ as containing an important deposit 
of flint fireclay. The location of tiie property is shown on Plate X, 
under Riverside County. The property consists of 1700 acres, and lies 
in an extremely rugged portion of the Santa Ana ^Mountains, south of 
Gypsum station on the Santa Pe i-ailroad. The deposit lay idle for 
many years, but since 1925 considerable development work has been 
done, which has demonstrated the presence of large deposits of flint 
fireclay and red-burning shale in the Upper Chico (Upper Cretaceous) 
formation. A view of one of the fireclay exposures is shown on ])hoto 
Xo. 28, and one of the red shale prospect pits is illustrated on photo 
No. 29. 

The flint fireclay, when dry, is gray to black in color, and has a 
conelioidal fraetur(\ The lighter-colored varieties have very much the 
appearance of chert, but can easily be scratched with a knife, and when 
ground with water, develop moderate plasticity.- It contains from 
34% to 40% of alumina, and is highly refractory. Sample No. 
282 was taken for testing, but should not be considered as representative 
of the deposit, as it is a grab sample from development workings. The 
results are on page 282. Sample No. 221 (page 330) of similar material, 

1 Prel. Rept. 7, p. 66, and Rept. XXI, p. 66. Listed under "Los Angeles Pressed 
Brick Companv." 

- In this connection, see Walker, T. C, The Effect of Pine Grinding on an Indurated 
Clay: Jour. Amer. Cer. Soc, Vol. 10, pp. 449-450, June, 1927. 



142 



DIVISION OP MINES AND MININO 



but of much poorer quality and containing a high percentage of iron, 
was also tevSted. 

The red-burning shale has been prospected at a number of points 
on the property. It is of value in the manufacture of red-burned vitri- 




■•^ 





* 



^"^^ 






A\ 



f^. 



t 

X 



I 



Photo No. 2S. Flint fire clay at iiortal of tunnel, Goat 
Ranch, Gladding. McBean and Company, Orange County. 
(Sample No. 282.) 

tied ware, such as sewer j)ipe and paving brick. ISample Xo. 223 (p. 
343) was taken and tested. 

La Bolsa Tile Company. G. W. Moore, president ; A. W. Griffith, 
secretary and manager ; E. R. Bradbury, superintendent. Home office, 



CLAY tTESOURCES AND CERAMIC INDUSTRY 



143 



Huntington Beach. This company lias been established for twenty 
years. The j)lant anci clay pit are two miles north of Huntington 
Beach at Weibling siding on the Soutliern Pacific Railway, adjoining 
the northern edge of the Huntington Beach oil field. The company 



r'^ 








-v' '* ^^W^- 


^^m^ljmMXi- ■ 


r 


^^™gi. !U9.Jim^ 


'JV^^^^^^^^I^^^^^^^^^^^^^^^I 


^^^^^^^^^^^^|Q|7 Jc 


"" 1 




■Bj^^^^ ' 





Photo No. 29. M -M 2 pit, Goat Ranch, Gladding, McBean and Company, 

Orange County. 




Photo No. .30. Plant of La Bolsa Tile Company, Weililinp, Orange County. 
(From State Mineralogist's Report XXI, p. 65, 1925.) 

o^\Tis 31 acres in Sec. 35, T. 5 S., R. 11 W., S. B. M. The products are 
drain tile from 3 to 20 inches in diameter, hollow building blocks, 
common brick, and more recently, ruffled face brick. Photo No. 30 is a 
view of the plant. 



144 DIVISION OP MINES AND MINING 

The cl;i,y is iiiiiicd lo a (l('i)th of five feet by a Pordson tractor, using 
a harrow for loosening and a scraper to deliver it to a hopper, which 
feeds a dry pan. An elevator delivers tlie ground material to a hopper 
which feeds a short inig-niill from which the clay passes to an auger 
machine. The plant is equipped with two auger machines which are 
used to shape all products except drain tile of 10 inches diameter or 
larger, for which purpose a vertical steam press is used. 

The drying sheds are heated by hot air forced by a blower through 
flues under the floor. The air is heated either by the exhaust from the 
kilns or by exhaust steam. Tlie drying sheds have a storage capacity 
of 60,000 tile. The drying cycle is from 24 to over 60 hours, depending 
on tlie size of the ware. 

The plant is equipped with three 28-ft. down-draft kilns, with a 
capacity of 70 to 80 tons of material each, and one 32-ft. kiln, with a 
capacity of 100 tons. Natural gas is generally used as fuel, but the 
plant is equipped for oil firing when needed. The firing cycle is 72 to 
80 hours to a maximum of 1650° F. 

The finished products are dense and hard with a good red color. Ten 
men are employed. 

Bibl: State Mineralogist's Report XXI, p. 66; Prel. Rept. No. 7, 
p. 66. 

Olive Roofing Tile Co. Ramon Flores, owner. This is a small plant 
near that of the Garber Brick antl Tile Com})any. Hand-made roofing 
tile is the only product. Surface clay from the property is utilized. 
One kiln is in use. 

The plant is a Mexican operation, and as many as 24 men are 
employed at times. 

Orange County Brick and Tile Company} F. C. Krause, president; 
Charles Page, secretary; W. J. Carmichael, general manager. The 
company owns nine acres in Sec. 9, T. 4 S., R. 10 W., within the city 
limits of Anaheim. 

The company is manufacturing building brick, and also produces 
sand for building purposes. The material used is unconsolidated sand. 
The sand is mixed with lime and cement in the following proportions : 
Common brick: lime 7|%, cement 2%. Face brick: lime 10%, 
cement 5%. 

Material from the sand ])it is transported by drag-line scraper to a 
hopper, from Avhich it goes to a })ucket elevator, elevated and then 
])assed through a revolving screen. Here it is sized into three different 
sizes ; the over-size and the minus 8-mesh going to storage bins, the fine 
sand to wet-grinding pan, where it is ground and then elevated to two 
bins, then sent on to the mixer from which it is fed to two American 
clay brick rotary presses. One press has a capacity of 8000 brick, the 
other 17,000 brick. The brick then are loaded on to cars and given 
10-hour heat treatment under 125 pounds pressure in two Hardinge 
cylinder driers. Tliese driers are 80 feet long by 6 feet in diameter. 
Heat for cylinder driers is furnished by 70-h.p. boiler, oil being used 
as fuel. The other equipment is driven by electric motors. Ten men 
are employed. 

^ By W. B. Tucker, 07;. cit., p. 60. While not a ceramic operation of the type being 
con-^iidered in this report, this descriiition i.s included here as of general interest, " 
it is tvnical of similar cjpeT'ations in various parts of the state. 



CLAY RESOURCES AND CERAMIC INDUSTRY 



145 



The Vitrefrax Company (O'Neill Ranch Fire Clay Deposit). On 
the Raiiclio de Santa ^Farj^arita, the <>reater portion of -wliich is now 
owned by the Jerome O'Neill I'aiiiily, are several excellent showings of 
high-grade fireclay, one of which has been leased and developed within 
the last few j^ears through the efforts of the Vitrefrax Company of Los 
Angeles. This deposit is 10.2 miles by i-oad east of San Juan Capis- 
trano, in Gabino Canon, close to the San Diego County line. The 
material consists of a white and blue-gray fireclay high in alumina, 
and quite free from ii'on stains. It is known locally as a bone clay, 
and in fact corresponds in analysis to that of typical bone clays, but 
without the distinctive jiisolitic structure of the type clays. The fire- 
clay bed is overlain by a thin bed of black carbonaceous ])lastic clay, 
which separates it from the overlying loosely con.solidated sandstone. 
Underlying tlie fireclay is a mottled ])lastic clay, similar in general 
appearance to the Alberhill i)ink-mottled variety. The thickness of the 




Photo No. ;>1. Vitrefrax Co. Entrance to upper chamber workings, O'Neill 
Ranch clay depo.sit. Orange County. (Sample No. 62.) 

fireclay, as exposed in the workings, is from 10 to 15 feet. The bed is 
flat-lying, with a slight westerly dip. A view of the deposit is shown 
on plioto No. 31. 

The clay is recovered by chamber mining, using posts where needed 
to support the overburden. At the time of visit, in July, 1925, an 
area of 70 by 25 feet had been mined and a 100-foot tunnel had been 
driven to the west of the chambers, and at a lower level, with the object 
of providing for gravity loading of small mine cars, by means of a 
raise to the clay bed. One of these raises had been driven nearly to 
the roof of the clay, and demonstrated that the total thickness of clay 
above the tunnel is nearly 20 feet. 

At several other localities in the vicinity are exposures of various 
grades of clay. It is likely that in the future, important clay beds will 
be developed and mined. 

10 — 54979 



146 DIVISION OF MINES AND MINING 

Samjile No. 62 was taken for testing. See page 259. 

Bibl (Clay resources of Orange County) : Repts. XV, 519; XXI, 
pp. 65-67. Prel. Kept. 7, j)]). 66-67. 

PLACER COUNTY. 
General Features.' 

Placer County extends from the Sacramento Valley on the west for 
a distance of 80 miles to the Nevada state line on the eastern slope of 
the Sierra Nevada, including the larger part of Lake Tahoe. The total 
area is 1395 square miles. The elevation increases gradually from near 
sea level on the west to mountain peaks 8000 to 9000 feet high along the 
summit of the range on the east, then descends to 6225 feet along Lake 
Tahoe. There is a corresponding variation in climatic conditions. The 
western part of the count}' below an elevation of 2500 feet supports 
most of its industries and nearly all of the population of about 20,000. 
In this region snow seldom falls below 2000 feet elevation and never 
lies on the ground below that elevation. The county seat, Auburn, is 
at an elevation of 1360 feet, and the di.strict from there westward 
through Newcastle, Penryn, Loomis and Rocklin is the most important 
deciduous fruit producing area in the state, Newcastle being the leading 
shipping point. The soil is mainly decomposed granite and granodiorite 
on the west and amphibolite schist and diabase near Auburn and to the 
east, until the granodiorite of the high mountains is reached. 

The Ogden route of the Southern Pacific system traverses the county 
from the Sacramento line to the summit of the Sierra Nevada, passing 
through the principal towns, and the Oregon branch of the same rail- 
road, leaving the main line at Roseville, passes northward through Lin- 
coln, serving the farming and clay Avorking industries there. Two state 
highways run about parallel to the two lines of railroad, one eastward 
from Sacramento over the mountains, and the other northward from 
Roseville along the east side of Sacramento Valley. A third state high- 
way runs north from Auburn to Grass Valley and Nevada City, in 
Nevada County. 

Taking its name from the Spanish, because of the richness of its sur- 
face gold placers, the county showed a great diversity of mineral 
resources at an early date, and was distinctly a mining county until 
about 1890, when fruit raising began on a large scale for eastern ship- 
ment. Lumbering and the summer grazing of cattle in the higher 
mountains have been less important industries. 

Gold has been the principal mineral ]n-oduct of the county, but since 
1920 the value of the pottery clay and brick production has exceeded 
that of the gold production. Since 1922, the value of pottery clay alone 
has been greater than that of gold. Other mineral products that have 
been produced commercially in recent years include miscellaneous stone, 
granite, silica (quartz), chromite and copi)er. Small tonnages of 
asbestos, manganese ore, magnesite, mineral paint and soapstone have 
been shipped at various times, and the limestone production of the 
county was at one time of importance. 

Clay Resources. 

A remnant of the lone formation, containing valuable clay deposits, 
occurs on the edge of the Sacramento Valley at Lincoln. Since 1875, 



> Logan. C. A., State Mineralogist's Kept. XXIII, pp. 235-237, 1927, 



CLAY RESOURCES AND CERA:\riC INDUSTRY 147 

this area lias been a elay produeiii^' and clay woi'kin*; center. Present 
prodnction from the district is between 12;"), ()()() and ir)(),0()0 tons 
annnally. Other remnants of the lone foi-mation occnr at varions ])laees 
in the county, ami cla\s have been found in other formations, but none 
of these have led to the discovery of commercial deposits. On account 
of the fact that the active clay workinji; industry centers about Lincoln, 
the discussion of the elay resources of the county is divided into two 
sections: the Lincoln District, and ^liseellancons Deposits. 

Lincoln District. 

At Lincoln is one of the three most inipoHant clay dejiosits in the 
state. The deposits undei-lie a fjroup of low hills that rise to a maxi- 
mum of 80 feet above the alluvial jilain of the Sacramento Valley. The 
clays are a remnant of the lone formation which was jirotected from 
erosion by a capping of andesite-agglomerate. As shown by C. N. 
Schuette,^ and illustrated in the vertical section through a portion of 
the jiroperty of the Clay Cor])()i-ation of Califoinia, |)late IX, the upi)er 
clay beds have been removed by erosion a short distance beyond the 
limits of the ])resent lava cap. Since the i)eriod of erosion, gravel, 
sand, and soil from the rivers and flood plains of the Sacramento Valley 
have raised the floor of the valley to its present level. 

In some ])laces the recent dej^osits abut against the margin of the 
lava cap, and in other {)laces they lie against the gently-slo])ing surface 
of erosion of the uj)])er clay beds, thus affording some exposures of 
elay which aided in the original discovery and development of the 
de])0sits. 

The clay beds lie ])ractically hori;^ontal, and are characterized by 
remarkable uniformity in thickness and quality- over large areas. 
Several different beds can be differentiated and are of sufficient thick- 
ness to permit separate mining. The ceramic ])roperties of the clays 
may be summarized as follows: The drying and fii-ing shrinkage is 
high, but shrinkage takes })lace with little danger of cracking. The 
fusion point lies between cone 28 and cone 33 ; fired colors range from 
light buff to light red; knife hardness develo])s near cone 1; vitrifica- 
tion is well advanced (less than 3';> absorption) at cone 13; and fired 
strengths are good, but with the highly-grogged mixtures necessary to 
avoid excessive shrinkage, the body strength may not be so high as is 
desired. The princijial uses are for architectural terra cotta, fire brick 
and stoneware. 

Clay Corporation of California, .lolin T. Koberts, ])resident. Home 
office, Kialto Building, San Francisco. The mining property of the 
Clay Corporation of California, a subsidiary of the Stockton Fire Brick 
Company, has recently been described by C. N. Schuette.- The descrip- 
tion that follows is ])artly based on ^Mr. Schuette 's article, and partly 
upon notes made by the Avriter when the property was visited on 
August 13, 1925, and again on June 25, 1926. 

The property is in Sec. 4 and 9, T. 12 N., R. 6 E., M. D. M. The 
area is covered by andesite-agglomerate from its southern boundary to 

■ Engineering Principles Applied to Exploitation of a Clay Deposit, Eng. and Min. 
Jour.-Press. Vol. 121, p. 964, June 12, 1926. 
- Op. cit. 



148 



DIVISION OF MIXES AND MINING 




Plate VIII. General arrangement of quarry and plant of the Clay 
Corporation of California, Lincoln, Placer County. (Reprinted 

by i)erniission of Engineering and Mining Journal.) 



I 



CLAY RESOURCES AND CERAMIC INDUSTRY 



14U 



K2- 









O o 



X 



150 



DIVISION OP MINES AND MINING 



a line roiij;lily i)ar;illel to and ai)i)roximately 1600 ft. north of the 
Lineoln-Marysville ]ii<>'hway. Drilliiiji' and test ))ittin^' shows that all 
of tlio chiy beds exposed in tlie adjoining property of the Lincoln Clay 
Prodncts Co. on the south ])ersist on an even grade, thickness, and 
character under the area covered by the lava flow, but that they do not 
])ersist northward as they had been removed by erosion before the 
deposition of the valk\y sediments. This condition is shown in the 
generalized north-and-south cross-section, plate 9. Over 1,000,000 tons 
of clay corresponding to the Lincoln Clay Products Co. No. 1-6, have 
been developed. 

The general arrangement of the quarry and i)lant is shown on plate 
VIII. Since the stripping is as thick or thicker than the underlying 
clay, the trackage was laid out to place the waste dump as near the pit as 
possible. The quarry starts on the north slope of the hill and is carried 
parallel to the trend of the hill, thus giving a pit face of sufficient 




Photo No. 32. End-cut during preparation of pit of Clay Corporation of Cali- 
fornia, at Lincoln, Placer County. (Samples No. 152 and 153.) 

length to yield a full season's tonnage at one cut. The pit face is 1700 
feet long. , 

The ])it equi])ment consists of a f-cu. yd. gasoline shovel, an 8-ton 
gasoline locomotive, ten 8-yd. rocker dump cars, and two flat cars. 
Thirty-])ound rail and o6-in. track grade is used, with a maximum of 
2% grade. Photo No. 32 shows the shovel at work during the prepara- 
tion of the pit. 

Tlie clay storage ])lant was designed with the object of .securing a 
thorough mixing of the clay as received from the pit, and to remove as 
much water as possible before sliipping. The clay is crushed to 2^ in. 
in a 21 by 42 in. single-roll crusher. The crusher discharge is carried 
by an IS-in. belt conveyor to llie top of tlie storage building, where it is 
spread in a lliin layer over the surface of llie bin by a self-propelled, 
self-reversing 1rii)])er. Drying by the hot summer air sweej)ing tlirough 
the building is very etfective. A concrete reclaiming tunnel under the 
floor of the storage building is equipped with hand-operated gates to 



I 



CLAY RESOURCES AND CERAMIC INDUSTRY 151 

dischar^^e the clay to an 18-in. belt conveyor, which carries it to a cross- 
tunnel at one end of the building, where the clay is delivered to an 
inclined-belt conveyor, 18 in. wide, running up to the top of the three 
oO-ton storage bins in the mill building. 

From the end bin the clay can be drawn directly into railroad cars 
on the spur track. PVoni either or all of the bins, the clay can be fed 
by apron feeders to a chute leading to a five-roller low-side Raymond 
mill. The ])ulverized clay is blown to a cyclone collector in the toj) of 
the mill building, and is delivered to any one of three -lO-ton bins, which 
are fitted with three sacking spouts each. The sacked clay is stored in 
the building while awaiting shipment. 

The pit is o])erated in the dry season between ]\Iay and December. 
The minimum operating force consists of the superintendent, two men 
on the shovel, two men on haulage, and two men to operate the plant. 
Two or three extra men may be required from time to time, and at the 
beginning of the season a track gang is employed for two weeks to 
prepare the track for the season's operation. Two men attend to 
shi|)|nng and pulverizing in the winter. 

The capacity of the i)lant, from pit to storage, is three 5-car trains 
])er hour, or slightly over 540 tons ])er 8-hr. day. The maximum 
capacity of the storage building is 18,000 tons. The total annual 
capacity of the plant when operated as described is 50,000 tons. This 
could be increased without extra equipment by two-shift operation 
during the summer, with storage of pulverized clay, as well as crushed 
clay, at the beginning of winter. 

The storage and pulverizing plant require 192 hp., distributed as 
follows : 

Horsepower of 
Unit driving motor 

21 by 42-in. single-roll crusher 40 

18-in. conveyor, 366 ft. long 20 

18-in. reclaiming conveyor, 265 ft. long 15 

18-in. cross conveyor to mill building, 172 ft. long 15 

Bin feeders 2 

Raymond mill 60 

Raymond mill fan 40 

Total -- 192 

]\Iiscellaneous electric ])ower used on the property include a com- 
))ressor for oi)erating rock drills, a inimji for draining the pit, and a 
lighting system. ^ 

Samples : At the time the pit w^as sampled, on August 13, 1925, the 
cut had not been carried to the bottom of the bed that corresponds to 
the No. 1-6 clay (sample No. 146, p. 303) on the pit of the Lincoln 
Clay Products Co. Two samples were taken, however, both of which 
overlie the No. 1-6 clay. In 1926, a sample of prepared clay was 
obtained from the company, and was tested under No. 280. 

No. 152 is a plastic clay lying in a 6-ft. bed beneath the capping. 
The test results are given on i)age 304. No. 153 (p. 299) is a less 
]ilastic clay from a 3 to 4 ft. bed underlying No. 152. It is one of the 
clays included in the No. (sample No. 145, p. 291) clay of the Lincoln 
Clay Products Co. No. 280 is more re|)resentative of the material 
available during the normal operation of the pit. (See page 305.) 

GJaddhui, McBran and Company. Lincoln Plant. Athnll McP>ean, 
president; A. L. Gladding, vice president. General offices, 660 Market 



152 



DIVISION OP MINES AND MINING 



Street, San Francisco. Chas. Gladdino-, manager at Lincoln. The 
Lincoln ])lant of Gladding', McBean & Co. was established in 1875, and 
has operated continuously since that time. The compa):y was incor- 
porated in 1886, and has steadily expanded the scope oi its operations 
until at the present time it is the largest clay products manufacturing 
organization west of the Mississipi)i Valley. The company now owns 
three large plants, one at Lincoln, one at Glendale, Los Angeles County, 
and the third at Auburn, Washington. It has recently acquired control 
of the Los Angeles Pressed Brick Co., operating several large plants in 
southern California, and of the Denny-Renton Clay and Coal Co. of 
Seattle, Washington, operating two plants in Washington and one at 
Portland, Oregon. 

The Lincoln plant specializes on architectural terra cotta, fire brick, 
face brick, roofing tile, sewer pipe, chimney pipe, and garden pottery. 
A fine example of the use of architectural terra cotta manufactured at 




Photo No. 33. Clay pit of Gladding, McBean & Co., at Lincoln, Placer County. 

Lincoln is the new Russ Building in San Francisco. Photo No. 1 
(frontispiece) is a view of this building. Many other important 
buildings on the Pacific Coast have been faced with terra cotta from 
one of the company's plants. 

Clay Deposit: The company owns 480 acres of clay land in Sec. 9 
and 10 of T. 12 N., R. 6 E., M. D. M. The present working pit, shown 
in photo No. 33, is in the SE]- of Sec. 9. A section through the pit is 
as follows : 



Section Through Pit of Gladding, McBean & Co., at Lincoln. 

Sample Test data Thicknes.s, 

No. on page Character of material feet 

Lava: Andesite-agglomerale S 

155 325 Pit sand : Iron-stained clay, sand and fine gravel 10 

Sand and gravel, not usd 15 

156 299 Fire-proofing clay, corresponding in quality and thick- 

ness to L. C. P. Co., No. 0, sample No. 145 7 

157 304 Terra cotta clay, corresponding in quality and thick- 

ness to L. C. P. Co., No. 1-G, sample No. 146 15 



CLAY RESOURCES AND CERAMIC INDUSTRY 153 

Data Avere not availablo for definitely determining the correlation 
with the clay beds exposed on the properties to the north, but it seems 
])robable that the fire-proofingr clay, sample No. 156, corresponds to the 
No. clay of the Lincoln Clay Products Co., sample No. 145, and that 
the terra cotta clay, sample No. 157, corresponds to the No. 1-6 clay, 
sample No. 146. The overlyinj? sand and j>ravel beds in the Gladdinj;, 
IMcBean pit would indicate that the lava cap was laid down on this 
area before these beds were eroded, whereas to the north most of the 
material overlyinji- the clay beds had been removed before the deposition 
of lava, and in some places the ujiper clay beds themselves had been 
partly encroached upon by erosion. However, the bed underlying the 
terra cotta clay is of similar material, which indicates either that the 
No. 7 and No. 8 clays of the Lincoln Clay Products Co. are absent here, 
or that the correlation does not hold. 

I\IiNiNG : The clay is mined by steam shovel in benches, as shown on 
photo No. 33. The pit is over 1100 ft. long:. Waste is carried to the 
dump, and clay to the plant, on an industrial railroad, with a steam 
locomotive and 5-ton dump cars. The production of clay is at the rate 
of approximately 500 tons per day during the dry season. Water that 
runs into the pit during the winter is pumped out at the beginning of 
each dry season, and little pumping is ordinarily required during the 
summer. 

Plant: The plant occupies a 25-acre tract, on the northern edge of 
the town of Lincoln, and nearly one mile southeast of the clay pit. An 
airplane view of the ])lant is shown on photo No. 34. In addition to 
clays from the local pit, clay and sand from lone, clay from Natoma, 
quartz from various sources, and grog are used in the body mixtures. 
In the design and operation of the plant, extreme care is used to ensure 
uniformit}^ of raw materials, and accuracy of body proportioning. 
I'pon being delivered to the plant, all materials are stock-piled sepa- 
rately in a covered shed. A 4-tou traveling crane reclaims the mate- 
rials and delivers them to one of nine small bins, which feed four dry 
pans, o])erated to grind through a 14-mesh screen. The ground mate- 
rials, still se])arate, are then elevated to storage bins. The body mix- 
tures are proportioned from these bins by means of disc feeders. 

The terra cotta body mixture contains approximately 50% terra 
cotta clay, 10.0% non-plastic clay, and 40.0% grog, by volume of minus 
14-mesh material.^ 

The body mixture is prepared by double pugging, and the average 
water content of the wads is 26%. The wads are aged under damp 
burlap in cool rooms before being sent to the pressers, but the minimum 
aiding period is often only two or three hours. The pressing room has 
no unusual features. All of the terra cotta and garden pottery are 
shaped by hand pressing in plaster molds. 

Terra cotta, roofing tile and electrical conduit are dried in Carrier 
ejector humidity driers, which are designed to give accurate control 
over the four factors of time, temperature, humidity and velocity during 
drying. Tlie drying cycle in use at the time of visit on August 14, 
1925, was as folloAvs: The drying atmosphere began with five hours at 
]20° F. and 60% humidity was increased by steps to 212° and 50% 

' Larkln. P. G., and Curry, E. R., Notes on Terra Cotta Body Shrinkage, Jour. Am. 
Cer. Soc. Vol. 8, p. 113, 1925. 



154 



DIVISION OP MINES AND MINING 




a 

CIS 

a 

a 

o 
o 



m 

5 

o 
o 



5 

6 












bJ] 



O 

'A 

o 

o 
K 



CLAY RESOURCES AND CERAMIC INDUSTRY 155 

humidity, in a period of five hours, tlien Avas held at 212° F. Avith 
urailually decreasing; humidity for 12 hours, and the ware was finally 
drawn about one hour later. The averagre dryinjr cycle thus occupied 
23 hours. Waste-heat tunnel driers are u.sed for firebrick and face 
brick. 

Eleven down-draft oil-fired muff}e kilns are in use for terra cotta 
firing. The body and glaze mature together at cone 4 (2000° P.), with 
a heating schedule of nearly four days. Four days are allowed for 
cooling, and three days for unloading and setting for the next burn, 
making the turn-over time 11 days. The average total linear shrinkage, 
on a plastic basis, is 6.9%. The body color is buff. 

Fire brick are made from a mixture of terra cotta clay (sample No. 
157), ground fire brick grog, and fpiartz. The brick are shaped in a 
side-cut auger-machine. Three round down-draft kilns are usually in 
use for firing fire brick. The firing cycle occu])ies five to six days 
firing, and about an equal time cooling. The finishing temperature 
corresponds to cone 11 down, or 1285° C. 

Face brick are made from local materials, using all three of tlie 
materials mined in the company's pit, proportioned according to colors 
desired. Practically all the face brick produced in the ])lant is buff 
or cream color. An angei- machine shapes the brick, which are either 
end- or side-cut. They are fired to 2200" F. in round down-draft kilns, 
four of which are usually in use for this class of ware. 

The sewer ])i])e mixture contains 'fire-proofing clay' (sample No. 
156), Tone sand and grog. Electrical conduit is made from the same 
mixture, with the addition of some Natonia clay (samjjje No. 212, j). 337). ^'P 
Twelve round doAvn-draft kilns are in service on these two classes of %^ 
ware, firing to a maximum tem]ierature of 1200" C. in about seven 
days, including the salt glazing period, then cooling for a nearly equal 
period. 

Roofing tile is made from a mixture of local materials and Natoma 
clay. Drain tile is made from a similar mixture. Both are shaped on 
an auger machine. The roofing tile is fired in a tunnel kiln, 363 feet 
long, with a 43 hour cycle to a maximum temperature of cone 3 
(1145° F.). Studies made at the plant liave demonstrated a saving of 
50% of the fuel consumption of a round down-draft kiln for this class 
of ware. 

In addition to the products already mentioned, flue lining is manu- 
factured. Four round down-draft kilns are in use for firing this 
product. 

All the firing is done with oil fuel, atomized by compressed air. A 
complete pyrometric control of all kilns ensures uniform firing condi- 
tions, and economy of fuel. Electric i)Ower is used throughout the 
plant. 

The plant contains an architectural and sculpturing dej)artment. a 
drafting department, and a ceramic laboratory. As in most plants 
specializing in architectural terra cotta, the staff of the ceramic labora- 
tory spend the greater i)art of their time developing glazes. 

About 600 men are emi)loyed in the plant, of Avhom a large proportion 
are on ])iece work. A summary of the kiln equi])ment and the ap])roxi- 
mate annual ca])acity of various classes of ware are given in the follow- 
ing table : 



/. 



156 



DIVISION OF MINES AND MINING 



Kiln Data and Approximate Annual Capacity of Gladding, McBean & Co. Plant 

at Lincoln. 

Firing' 

No. of Type of Max. temp., time, Annual 

Class of ware kilns kiln °F. days capacity 

Arcliitectural terra cotta- 11 Muffle d.d. 2000 3.75 12,000 tons 

Sewer pipe and conduit 12 Round d.d. 2190 7 20,000 tons 

Face brick 4 Round d.d. 2190 6 3,200 M 

Firebrick 2 Round d.d. 2370 6 1,600 M 

Chimney pipe 4 Round d.d. 1830 4 3,000 tons 

Drain tile Set with other ware 

Roofing tile 1 363 ft. tunnel 1975 43 hrs. 12,000 tons 

Garden pottery Occasional 

Lincoln Clay Products Co. M. J. Dillman, president, Lincoln. The 
Lincoln Clay Products Company has no manufacturing plant, and is 
exclusively engaged in the mining of clays. ^ The property is located two 
miles northwest of Lincoln, in "the N| of Sec. 4, T. 12 N., R. 6 E., 
M. D. M. It has been in operation for over thirty years. 




Photo No. 35. General view of the pit and plant of the Lincoln Clay Products 
Co., looking south from the top of the storage building of the Clay Corpora- 
tion of California. The Clay Corporation's offlce building is in the right 
foreground. 



The pit is w^orked in benches by a combination of a spiral a])proacli 
and an incline as shown in photos Nos. 35, 36 and 37. Benches are 
established on the bottom of each clay bed, or series of beds, that is to 
be mined separately. Gasoline locomotives are used to haul train- 
loads of stripping or clay from the upper beds and an incline hoist is 
used to remove the clay that is mined near the bottom of the pit. The 
pit is over 1200 feet long and 600 feet wide and the maximum depth is 
60 feet. 

The clay is loosened by hand di'illing and blasting. A IJ cu. yd. 
gasoline shovel is used for loading clay from tlie thicker beds, and hand 
loading is used on the thinner beds. Five gasoline locomotives are in 
service. Two of these weigh three tons and the others weigh four, six, 

' A clay-working plant i.s contemplated in the near future. 



CLAY RESOURCES AND CERAMIC INDUSTRY 



157 




Photo No. 36. Eastern end of pit of Lincoln Clay Products Co., near Lincoln. 
Samples No. 145 to 150 were taken from the pit. 




Photo No. 37. Western end of pit of Lincoln Clay Products Co. with clay 
grinding and storage plant of the Clay Corporation of California in the 
middle background. 



158 DIVISION OF MINES AND MINING 

and eip:ht tons, respectively. A eentrifn^al ])um]) is used to remove 
run-otf water from the pit. 

A section tlirougli the pit follows : 

Average 
Sample Test data thicknes.s, 

No. on page Class of material feet 

Soil and gravel 1- 3 

Lava 1- 6 

145 291 -Xo. clay: Face brick body 8 

146 303 No. 1-6 clay: Terra cotta body 1 .o 

147 303 No. 7 clay : Tile, face brick, sewer pipe. High in iron. 12 

148 336 No. 8 clay: Higher in iron than No. 7 6 

149 298 No. 9 clav : Similar to No. 1-6 8 

150 291 No. 10 clay: Similar to No. 9 22 

A larjre storage shed, shoAvn in photo No. 35, provides storage of 
clay during the rainy season, allows for fluctuations in mining and 
shipping during the season, ensures a certain degree of mixing to mini- 
mize the effect of local variations in the quality of clay, and permits 
seasoning of clay for those customers who so desire. 

In the fall of 1918 a washing plant was built for the purpose of 
investigating the commercial pos.sibilities of marketing a waslied 
product. The clay was ground in a Graupner centrifugal mill, mixed 
with water, and settled in vats. The thickened slip was dipi)ed out by 
hand and sun-dried in shallow trays. The principal effect of tliis 
process was to eliminate a certain proportion of the sand that is present 
in the raw clay, thereby producing a finer grained clay that has a more 
uniform, but greater, shrinkage. On account of high freight rates on 
washed clay, compared to crude clay, and because of the fact that the 
washed clay did not ]iossess sufficient advantages in use, washing was 
discontinued after a brief period. In order to permit a study of the 
properties of the washed material, ]\Ir. Dillman kindly gave tlie writer 
a sack from the warehouse. This is sample No. 151, and the test 
results are given on page 303. 

An average of 12 men are employed. The annual output varies with 
market demands, but is usually in excess of 50,000 tons. The selling 
price of the clay, f. o. b. cars at the plant, averages $1.75 per ton. 

Miscellaneous Deposits. 

Previous publications^ by the State Mining Bureau have reported 
occurrences of clay at various points along or near the line of the 
Southern Pacific Railroad, from Alta to Gorge. The most i)romising 
of these were visited in August, 1925, and were in each case found to 
be derivatives of the andesitic tuff-breccias, rhyolite tuffs, or volcanic 
ashes that are remnants of the great Tertiary volcanic deposits that at 
one time completely covered the basement rocks of tlie west slope of 
Sierra Nevad? Mountains, before the more recent period of tilting and 
stream cutting that has resulted in the ])resent topography. Rock 
decomposition and alteration has i)rogre.ssed to a varying degree in 
many of these materials, with the result that in places there are exten- 
sive beds of fine-grained, white, greenish-white, or yellowish-white 
material having a certain degree of plasticity that are often mi.staken 
for useful clays. They are, however, of no value for ceramic ])urposes, 
on account of high drying and firing shrinkage, low cohesion in the 
partly-dried condition which results in serious cracking during drying, 

» Prel. Rept. No. 7, p. 67-73. 



CLAY RESOURCES AND CERAMIC INDUSTRY 159 

low fusibility, and dii'ty yollnw or red firiii<i- colors. Even if tlioy can 
be successfully dried without crackiui:-, the excessive sliriukajre will 
cause warping-, aiul they are i)ractically impossible to fire without 
splitting. A characteristic feature tliat renders easy the field elimina- 
tion of such materials is the spongy, sticky plasticity developed upon 
the addition of water, coujjled witli the large amount of water that the 
material will absorb to (Un-elop this 'plasticity,' usually amounting to 
over 75% of the solids by weight. 

As representative of this class of material, samjdes No. 161 to 165, 
inclusive, were taken, and two of them, No. IGl and 163, were submitted 
to a portion of the ceramic tests. 

Sample No. 161 was taken from a 50-foot railroad cut, 1 mile west 
of Gorge, between mile 157 and 158 on the railroad. The bed sami)led 
was 6 to 8 feet thick, and is exposed for a length of over 300 feet in the 
cut. It is overlain by 12 feet (maximum) of overburden on the south 
side of the cut, consisting of gravel and decomposed andesite, and is 
underlain by white rhyolitic tuff (?). The sample developed sticky 
plasticity with 71. 5/t water, and with less water was merely spongy 
Avithout much cohesion. The test pieces all sjilit badly during drying, 
and while hard, were very brittle. The calculated linear drying 
shrinkage, based on dry length, was 28.5%. It was not possible to 
obtain the dry transverse strength of the undiluted material, and the 
test pieces were not fired. 

Samples No. 162, 163, and 164 were taken from successive beds (top 
to bottom) of material exi)osed along the highway 0.9 mile above 
Baxter, or 2.1 miles above Towle. Each bed is approximately 2.5 feet 
thick, and the series is exposed for a distance of over 100 feet. It is 
overlain by from to 3 feet of white sand tuff. Some tests were made 
on No. 163, but tlie others were discarded. The plastic working prop- 
erties of sample No. 163 are similar to those possessed by sample No. 161, 
except that the presence of a larger amount of non-plastic material 
soriiewhat modifies the stickiness. The water of plasticity is 67.1%, 
the calculated linear shrinkage, dry basis, is 18.4% and the total drying 
and firing slirinkage to cone 06 (1005° C.) is 22.1 per cent of the plastic 
length. Visible drying cracks did not develoji, but the erratic results 
obtained from dry transverse strength tests indicates the presence of 
lines of weakness. All of the fired pieces cracked badly. (See page 350.) 

Sample No. 165 was from a railroad cut 1100 feet above (east) of 
Alta station, described ami illustrated in Preliminary Report No. 7, 
l)age 73. The exposed face is 35 feet thick and 600 feet long, con- 
sisting of alternating layers of fine grained yellowish i)lastic 'clay,' 
and of a sandier and whiter variety of the same material, overlain by 
red decomposed andesite varying from two to eight feet in thickness. 
The portion sampled was from a yellowish plastic bed varying from 
four to ten feet in thickness, midway between the top and bottom of 
the exposure. No tests were made other than pugging a small portion 
of the material with water and noting its general similarity to the 
materials represented by samples No. 161-164. 

Valleij View Mine. Owned by Judge J. B. Landis and Ed. Gavlord, 
of Auburn. Tliis property is in SE^ Sec. 12 and NEj Sec. 24, T. 
13 N., R. 6 E., M. D. ]M., eight miles by road northeast of Lincoln. 



160 



DIVISION OF MINES AND MINING 



Under tlio name of Wliiskoy Hill or IIar])ondino; Mine, it was Avorked 
for «>'old in the sixties, but later developeil into a eojjper pi-operty. In 
the lower workingis, sphalerite and pyrite increased in quantity and the 




Photo No. 38. Valley View Mine, Placer County. Portal of lower tunnel. 
(Sample No. 261 from glory hole that connects with the tunnel.) 




Photo No. 39. Valley View Mine, Placer County. Upper workings. (Sample 
No. 262 from bank to left (east) of center of view.) 

copper minerals decreased. There has been no production since 1918. 
The ore occurs in part in altered dikes which intrude the amphibolite 
schist country rock. In the upper workings, still accessible through a 
tunnel, a glory hole, and an open cut, the dike rock has been kaolinized. 



CLAY RESOURCES AND CERAMIC INDUSTRY 161 

The degree of kaoliiii/fitioii and tlie percentage of iron vary eonsid- 
eral)ly in different i)arts oi' tlie exposures, but in places the material is 
well kaolinized, lias fair plasticity, and is comparatively free from iron. 
Photos No. .'58 and 8i) are views of the property. Three samples were 
taken. No. 2(il (p. o2S) was taken from an undci-ground cliamber that 
connects by a chute to the tunnel, the i)ortai of which is shown on photo 
No. 38. The sample represents a small kidney of kaolinized material, 
exposed over an area about 10 feet square, and at least 4 feet thick. 
A ])eculiarity of the sample is that while it is distinctly red-burning, 
it has a softening point of cone 28 (1615° C). No. 262 (p. 350) was 
taken from the open cut shown in photo No. 39, and is representative of 
the material from the bank to the left (east) of the center of view. 
Tliis material has little or no ceramic value. No. 263 (p. 292) is a 
sample of white kaolin from the same open cut. It occurs as small 
isolated pockets, some of which are clearly shown on the right-hand 
side of photo No 39 as white patches. The material is nearly wiiite- 
burning. has fair pla.sticity, and a high softening temperature (cone 
32-33, about 1720° C). Unfortunately, thei'e is little indiccition that 
large bodies of equally good material will be found on the property. 

Bibl (Vallev View Mine) : Cal. State Min. Bur. Bull. 50, p. 174. 
Kept. XV, pp. 327-330; XXIII, pp. 246-247 and 286. 

RIVERSIDE COUNTY. 
General Features. 

Riverside County lies in the southern portion of the state. It is 
bounded on the north by San Bernardino County, on the east by the 
state of Arizona, on the south by Imperial and San Diego counties, and 
on the west by Orange County. The county has an area of 7420 square 
miles and a population of 60,297 (1920 census). It is the fourth 
county in size and the seventh in regard to the total value of mineral 
output (1925). 

The surface of Kiverside County, like that of much of southeastern 
California, is characterized by bare mountain ranges, separated by 
nearly-level arid belts of varying width. The minor ranges of moun- 
tains rise abruptly from the desert plains, having the appearance of 
being the summits of larger ranges whose bases are buried beneath the 
loose deposits of the desert. The San Bernardino and San Jacinto 
mountains are the most prominent ranges, the peaks of which rise to 
more than 10,000 feet above sea level. On the western edge of the 
county, and sei)arating it from Orange County, is the Santa Ana Range. 

Geology. 

A detailed study of the geology of Riverside County has not yet been 
made. In the desert areas of the eastern portion of the county, the 
principal formations, besides Quaternary gravels, are pre-Cambrian 
and Paleozoic metamorphics ; some Tertiary sediments, mostly Pliocene ; 
and various plutonic and volcanic rocks. In the western portion of the 
county, near Orange County, are extensive areas of Triassic, Upper 
Cretaceous, Eocene and Miocene age.^ 

» Smith, J. p., The geologic formations of California : State Min. Bur. Bull. 
72 and Geological Map. See also for bibliography ui- to date of issue in 1916. 

11 — 54979 



162 DIVISION OF MINES AND MINING 

The mineral resources of the county incIivJo V^rick, cement, clay, coal, 
copper, feldspar, gems, gold, gypsum, iron, lead, limestone, manganese, 
magnesite, marble, mineral paint, mineral water, salt, soapstone, silver, 
miscellaneous stone, and tin. In 11)25, seventeen dift'erent minerals 
were commercially produced, the most important being, in the order 
of their production, cement, miscellaneous stone, brick and hollow 
building tile, pottery clay, silica (quartz), granite, feldspar, and lead. 

Clay Resources. 

The Alberhill-Corona district in western Riverside County is one of 
the three most important clay producing areas in the state. The clay 
deposits extend in a belt along the Temescal Valley for fifteen miles 
from Elsinore on the southeast to Corona on the northwest. The clays 
were laid down in Eocene time, when the Temescal Valley was an arm 
of the sea opening northward into the valley of western San Bernardino 
County and extending southerly to Temecula. The width of the basin 
is from one to two miles, and the depth in places is over 600 feet. A 
property map of the district is given on plate X. 

The general character of the deposits is well described in the follow- 
ing excerpts from an article by the late J. H. Hill,^ then president of 
the Alberhill Coal and Clay Company, the largest producer in the 
district : 

"At the Alberhill pits, the clays present a wide diversity of color, character, and 
degree of consolidation. An extraordinary variety is found, including siliceous fire- 
clays, ball clays, plastic white- and buff-ljurning clays, highly aluminous and very 
refractory clays, numerous red-burning clays, and an extensive bed of material from 
which a china clay is obtained by v^ashing. A bed of lignite coal ranging from two 
to eleven feet in thickness occurs conformably with the clay strata, and adjacent to 
this the best fireclays are found. The strata are regular and persistent, and dip to 
the southwest with an average value of 10 degrees, with local variations due to an 
undulatory or wavy folding. 

"Minor local disturbances appear to have prevailed at Intervals during deposition 
of these clays, and coarse sandy beds are interspersed with fine-grained plastic clays. 
In these sandy beds, the coarse silica sand is often intermixed in a sporadic and 
irregular fa.shion with the accompanying clay substance. Mottled clays apparently 
due to simultaneous deposition of different kinds of sediments derived from separate 
sources are also found. The beds in general seem to indicate that long quiescent 
periods during which fine-grained clays were laid down were preceded and followed 
by stormy periods when frequent freshets or strong tidal currents brought in coarse 
silica sand and granite debris from surrounding highlands. The top soils of the 
region consist of debris of disintegrated granite, and vary from, a few inches to 
many feet in thickness. 

"Owing to the masking of the surface by the layer of disintegrated granite 
material, the total extent of the Alberhill deposit has not yet been fully determined. 
However, a large number of bore holes have been put down on widely separated 
portions of the property, and in every case clays of good quality were found to the 
full extent of the hole in depth. From this and other evidence, it seems quite 
probable that the entire mass of the small moimtain. above the valley floor and for 
an unknown depth, is clay. A few isolated occurrences of shale have been noted. 
Exploration to date has been sufficient to indicate beyond doubt that the quantity of 
readily available clay is so vast as to be inexhaustible for all practical purposes. 
* * * The hill comprising the deposit is about two and one-quarter miles long and 
one mile in width, with an average elevation of 16S0 feet. The main line tracks of 
the railway * • * are at an elevation of 1277 feet. * * * The present pits 
are all somewhat above the level of the railroad tracks." 

While Mr. Hill's estimate of clay reserves may have been somewhat 
optimistic, in the light of more recent work which indicates that the 
deposits lie in the form of a synclinal trough again.st the eroded surface 
of the mountain ranges on each side of the valley, it is substantially 
true that the supply of readily available clay is sufficient to last for 
many years, even at increased rates of production. Considering the 
district as a whole, the principal deposits lie on the eastern side of the 

* Clay deposits of the Alberhill Coal and Clay Company : State Mineralogist's 
Report XIX. pp. 185-210, 1923. 



CLAY RESOURCES AND CERAMIC INDUSTRY 



163 



[it deposits in the floor of the vallev and toward the western 

" ' * '^ "■ '• "•- and 

Uey 
e of 

)OUt 

ittle 
■rial 
tion 
eific 
)elt, 

1 or 
jecn 
oad 
low 



/ 



A 



^KM.^A. t Vyj. wC4,XJ. 



ine. 

ate 
uls 

dts 
mt 
nts 
the 
s a 
ed. 

•er, 

3p- 

oal 

x^ed 



to work the coal beds that occur here, and for 13 years previous to 
1895 the property was developed solely as a coal mine. The production 



162 DIVISION OF MINES AND MINING 

The mineral resources of the county inelu'Je V^rick, cement, clay, coal, 
copper, feldspar, gems, gold, gypsum, iron, lead, limestone, manganese, 
magnesite, marble, mineral paint, mineral water, salt, .s()ai)stone, silver, 
miscellaneous stone, and tin. In l!)2o, seventeen ditferent minerals 
were commercially produced, the most important being, in the order 
of their production, cement, miscellaneous stone, brick and hollow 
building tile, pottery clay, silica (quartz), granite, feldspar, and lead. 

Clay Resources. 

The Alberhill-Corona district in western Riverside County is one of 
the three most important cla}^ producing areas in the state. The clay 
deposits extend in a belt along the Temescal Valley for fifteen miles 
from Elsinore on the southea.st to Corona on the northwest. The clays 
were laid down in Eocene time, when the Temescal Valley was an arm 
of the sea opening northward into the valley of western San Bernardino 
County and extending southerly to Temecula. The width of the basin 
is from one to two miles, and the depth in places is over 600 feet. A 
property map of the district is given on plate X. 

The general character of the deposits is well described in the follow- 
ing exceri)ts from an article by the late J. H. Hill,^ then president of 
the Alberhill Coal and Clay Company, the largest producer in the 
district : 

"At the Alberhill pits, the clays present a wide diversity of color, character, and 
degree of consolidation. An extraordinary variety is found, including siliceous fire- 
clays, ball clays, plastic white- and buff-burning clays, highly aluminous and very 
refractory clays, numerous red-burning clays, and an extensive bed of material from 
which a china clay is obtained by washing. A bed of lignite coal ranging from two 
to eleven feet in thickness occurs conformably with the clay strata, and adjacent to 
this the best fireclays are found. The strata are regular and persistent, and dip to 
the southwest with an average value of 10 degrees, with local variations due to an 
undulatory or wavy folding. 

"Minor local disturbances appear to have prevailed at intervals during deposition 
of these clays, and coarse sandy beds are interspersed with fine-grained plastic clays. 
In these sandy beds, the coarse silica sand is often intermixed in a sporadic and 
irregular fashion with the accompanying clay substance. Mottled clays apparently 
due to simultaneous deposition of different kinds of sediments derived from separate 
sources are also found. The beds in general seem to indicate that long quiescent 
periods during which fine-grained clays were laid down were preceded and followed 
by stormy periods when frequent freshets or strong tidal currents brought in coarse 
silica sand and granite debris from surrounding highlands. The top soils of the 
region consist of debris of disintegrated granite, and vary from a few inches to 
many feet in thickness. v 

"Owing to the masking of the surface by the layer of disintegrated granite 
material, the total extent of the Alberhill deposit has not yet been fully determined. 
However, a large number of bore holes have been put down on widely separated 
])ortions of the property, and in every case clays of good quality were found to the 
full extent of the hole in depth. From this and other evidence, it seems quite 
probable that the entire mass of the small mountain, above the valley floor and for 
an unknown depth, is clay. A few isolated occurrences of shale have been noted. 
Exploration to date has been sufficient to indicate beyond doubt that the quantity of 
readily available clay is so vast as to be inexhaustible for all practical purposes. 
• * * The hill comprising the deposit is about two and one-quarter miles long and 
one mile in width, with an average elevation of 16S0 feet. The main line tracks of 
the railway • * * are at an elevation of 1277 feet. * * * xhe present pits 
are all somewhat above the level of the railroad tracks." 

While Mr. Hill's estimate of clay reserves may have been somewhat 
optimistic, in the light of more recent work which indicates that the 
deposits lie in the form of a synclinal trough against the eroded surface 
of the mountain ranges on each side of the valley, it is substantially 
true that the supply of readily available clay is sufficient to last for 
many years, even at increased rates of production. Considering the 
district as a whole, the principal deposits lie on the eastern side of the 

' Clav deposits of the Alberhill Coal and Clay Company : State Mineralogist's 
Report XIX, pp. 185-210, 1923. 




ri.ATK X, JTupcily riiiii] uf AUji.iliiil-Curiiiiu. diatiiL-t. Riverside Ouiiily. (By courtesy of Uubt. LiiUuii.) 



OV'J — facing page 1C2 



162 DWISION OP MINES AND MINING 

The mineral resources of the county inclu'le brick, cement, c 
copper, feldsDar, irems. Qokl. t>-vi)siini imn it.u,i i;,.ioc.+r>.,.^ -^- 

magnesit 
miscellan 
were con 
of their 
building 

Clay Resc 

The A 

the three 
deposits 
from Els 
were laid 
of the sec 
County a 
is from c 
property 
The ge 
ing exeer 
the Albe 
district : 

"At the 
degree of ( 
clays, ball 
refractory 
which a ch 
to eleven f. 
this the be 
the southw 
undulatory 

"Minor 1 
of these elf 
In these sj 
irregular f; 
due to simi 
sources art 
periods dur 
by stormy 
silica sand 
region con; 
many feet 

"Owing 
material, tl 
However, s 
portions of 
full extent 
probable th 
an unknow 
Exploratior 

readily ava 
* * * "J" 

one mile in 
the railwaj 
are all som 

While : 
optimistic 
deposits 1 
of the m( 
true that 
many yeg 
district af 




' Clay deposits of the Alberhill Coal and Clay Company : State Mineralogist's 
Report XIX, pp. 185-210, 1923. 



CLAY RESOURCES AND CERAMIC INDUSTRY 



163 



valley, but (loi)osits in the floor of the valley and toward the western 
side are of ini|)or1an('(' at a nninber of plaees. Foidinji', faultin^^, and 
erratic deposition aic most proiionneed on tiie eastei'n side of the valley 
ill the vicinity of Alhcrhili. The Emsco de])osit, on the same side of 
the valley, at an elevation of about 200 feet above the Moor, and abont 
six miles to the nortlnve.st of All)erliill (see maj), plate X), shows little 
evidence of structural complexity, and the character of the material 
ill the different beds is uniform over a lar.ue area. This same condition 
(u-evails at most of the west side pits, except the IMcKni^ht jiit (Pacific 
(May Products Company), near the northern limit of the clay belt, 
west of Corona, where the structure is more comi)lex. 

'Slant of the pi'omisin^' clay land in the district has been purchased or 
leased by various companies. The ac(|uisition of ])roperty has been 
particularly active since 11)24. when it became apparent that a railroad 
connection was to be made from Alberhill to Corona. This line is now 




6ectien Pas.'fs 
In Rear Of Mam P»t 



Pit 
\ 



\ 

rautt 



R.4. 
Bone 

Htd. 
m»tH€ 






Lignite 
Coat 



Pink 

= ~|m»ttK 



I'l.ATic XI. ] )iaf;rammjiti(; section of .strata at Alberhill, in a general west-east line. 
(From Slate Mineralogist's Report XIX, p. 1 90, 1923.) 



completed, and has not only resulted in a decrease in the freight rate 
from Alberhill to Los Angeles, but has eliminated long truck hauls 
throughout the district. 

Outside of the Alberhill-Corona district, few commercial clay deposits 
have been found in the county. Common clays are sufficiently abundant 
near the more populous i)arts of the county to serve all re((uirements 
for the manufacture of common brick. The desert portions of the 
county have not been thoroughly prospected for clays, and there is a 
chance that in the future a few interesting deposits will be discovered. 

Alberhill Coal and Clay Company. Chas. Biddle, general manager, 
Alberhill, California. This com])any owns nearly 2000 acres of prop- 
erty, parts of which are leased to other companies. The principal 
holdings are shown on plate X. The company was originally organized 
to work the coal beds that occur here, and for 13 years previous to 
1895 the property was developed solely as a coal mine. The production 



164 



DIVISION OP MINES AND MININO 




CLAY RESOURCES AND CERAMIC INDUSTRY 



165 



of clay started in 1S95 and it has been continuous since. The company 
lias no clay-working plants, but sells clays to many manufacturers 
throughout California, particularly in the Los Angeles district. More 
than thirty varieties of clav are mined and marketed. 




Photo No. 41. Alberhill Coal & Clay Company. Cut connecting main and west 
pits. 'Die AlVierhill plant of Gladding, McBean & Company (formerly 
Los Angeles Pressed Brick Company) is in the background. Riverside 
County. (From State Mineralogist's Report XIX, p. 189, 1923.) 




Photo No. 42. Alberhill Coal & Clay Company. One of the loading trestles. 
Riverside County. (From State Mineralogist's Report XIX, p. 191, 1923.) 

The operations of the company were described by the late J. H. Hill 
in an earlier report^ by the Bureau. For the sake of completeness, 
this article is freely used in the present report, with some additional 

'Hill, J. H., op. cit. 



166 



DIVISION OF MINES AND MINING 




■>-> m 
m 3 



3 H 
C " 



CD 



M 



0) 



^ 



bn 



^ T-1 



(X < 



IS . 



O bo o 

rt c 

o > w 

ti-i C cS 

^_> '^ o 



5 ^ >> 

■i-l >■ c 

O O 3 

r- • O 

5 So 

^ a> 

;- 5 ^ 

0; j^ > 

■* - J3 

o 
X 
|1< 



CLAY RESOURCES AND CERAMIC INDUSTRY 



167 




Photo No 44. AlberhiU Coal & Clay Company. Riverside County. 
An exposure of lignite coal. The clay stratum directly below 
the coal is SH-4 (sample No. 273) ; that directly above is SH-o 
(sample No. 28). (From State Mineralogist's Report XIX, 
p. 200, 1923.) 



168 



DIVISION OP MINES AND MINING 



details on recent developments. The reader is referred to Mr. Hill's 
article for further details not covered herein. 

Geological Section. An idealized geoloj?ical section of the Alberhill 
pits, as i)repared by Mr. Hill, is shown on plate XL This sketch is 
broadly generalized, and may be considered as a composite of the 
various beds, in their normal stratigraphic sequence. There is perhaps 
no locality on the property Avhere the series is complete, as some of the 
beds are thicker in one i)lace than in another, and other beds are 
entirely lacking in places. Burchfiel ' gives the following cross-section 
as being fairly representative : 

Kind of strata. 

Soil 

Yellow top clay 

Yellow main tunnel clay 



No. of feet 

3 
20 

6 
34 

6 

4 

4 
12 



Main tunnel clay 

Coal 

Bone clay No. W-105 

Clay between bone and blue clays 

Select west blue clay 

West tunnel blue clay 

Shale 




Plate XII. Handling and storage of clay bv the "glory-hole" method. 
(From State Mineralogist's Report XIX, p. 193, 1923.) 

Photos No. 40, 41, 43 and 44, all from Mr. Hill's article, illustrate 
various topographic and geologic features on the Alberhill property. 

Mining Methods. Wherever possible, the clays are mined by open- 
pit methods. The clays stand well in vertical banks up to 40 or 50 
feet in height. As operations are scattered, all loading is by hand. 
Glory-hole mining is used at various places. Underground mining by 
room-and-pillar methods is used where the overburden is thick, or 
where it is desired to mine special varieties of clay without removing 
overlying beds. In 1926, extensive underground operations w^ere 
started for mining the 'hill blue' clay, and it is expected that most of 
the production of this important variety will be obtained from these 
workings in the future, rather than from open pits. 

Plate XII, by Hill, illustrates the general method of glory-hole min- 
ing. Photos No. 40, 41, 43 and 44 illustrate various features of the 

'Burchfiel, B. M., Refractorv clavs of the Alberhill, California, Deposits: Jour. 
Amer. Cer. Soc, Vol. 6, p. 1167, 1923. 



CLAY RESOURCES AND CERAMIC INDUSTRY 



169 



iiiininfr ojioratinns, and photo No. 42 shows one of the loading trestles 
and bins Tor doliveriny tlic clay to railroad cars. 

At many of the pits, AvheelbarroAvs are used to deliver the clay to a 
loading chute, from which it is delivered by gravity into trucks for 
hanling to the railroad. At otlier pits, small mine cars are loaded by 
iiand, and are trammed by horses to the dumping points. In tlie glor\' 
holes and underground workings, mine cars are used. These are 
trammed by hand, with liorses, or by electric trolle.y locomotives, depend- 
ing upon tlie length of haul and average daily ]~»rodiiction nf the 
woi'kiiig. 

Tlie total ])rodiiction of clay from the company's property is about 
15,000 tons annually, and prices (f.o.b. Alberhill) range from $1.25 
])er ton for the ])oorer varieties, such as yellow stri])ping, to $5.50 ])er 
ton for some of the selected varieties of white-burning clay. .Most of 
the varieties sell for $2 to $3.50 per ton. The clays enter into the 
manufacture of a great diversity of products, ranging from china to 
lieavy structural wares. The diversity of clays makes it possible to 
produce many specialized wares. This is particularly true of the 
refractory and face-brick branches of the clay industry. 

Samples. Twenty-six samples from this property were tested. For 
convenience of reference, these are grouped below according to the 
clay classification adopted in this rejiort, which is fully described in 
Chapter IV. 



Sample Record, Alberhill Coal and Clay Company. 





Clay 


Clay 








Fircfl 


class 


sample 


Page 




Cone 


color 


number 


number 


reference 


Local nomenclature 


fusion 


White 


1 


11 


257* 


E-101 china clay 


28-29 






12 


257* 


E-102 china clay 


26-27 




2 


15 


264* 


Select main tunnel 


30-31 






28 


264* 


SH-3 


30 






29 


264*t 


Main tunnel (M.T.) 


30-31 




3 


273 


273*t 


SH-4 (ball clay) 


34 


Bull 


5 


17 


277*t 


W-105 bone clay 


34 






23 


277* 


West blue 


29 




6 


9 


287* 


Hill blue (1925) 


29 






14 


287 


A-clay 


31 






27 


287* 


No. 10 


30-31 






272 


292 


Hill blue, M.T. (1926) 


29 




7 


13 


296 


Extra select M.T. 


29-30 






271 


301 


Hill l)lup, lower tunnel 


31-32 






274 


302 


Hill l)lue, upper tunnel 


30 




9 


19 


311 


Diamonrl 


23 






2.5 


.•!ll*t 


West tunnel blue 


16 




10 


16 


314*t 


Select west blue 


18 


Red 


12 


8 


321 


Red clay No. 2 


19-20 






18 


321 


Clark tunnel mottled 


19 






24 


321 


West tunnel mottled 


18-19 






26 


321* 


West yellow 


not det. 




13 


7 


328* 


Pink mottled 


17 




14 


10 


334* 


Hill blue green 


14-15 






21 


334 


Sagger 


23 






22 


335 


Yellow Owl cut 


17 



* The properties of the.se A-arieties are also given by Hill, op. cit.. 
E-p2 varieties are discu.ssed under "D.C. clay." 

t The properties of these varieties are also "given by Burchfiel, o;?. 



The E-101 and 
cit. 



Emsco Clay Co. {Havringion Pit). Location: The Emsco Clay 
Company of Los Angeles has leased from John Harrington the Har- 
rington clay pit, in Sec. 35, T. 4 S., R. 6 W., in the Temescal Canon, 
10.5 miles by road southeast of the center of Corona, and 7 miles by 
road southeast of a loading siding on the southeastern side of Corona. 



170 



DIVISION OF MINES AND MINING 




o 

rv 

O 

o 
5 

03 

m . 

«^ 

c 

£>. 

o rt 
U o 

■D'O 

£5 

.i. c 

.c 
53 a 

o.S 

U be 

S'rS 



H c 

m .^ 

4) o 

So 
a ft 

bBo! 



i-j 



" fc. 

c« 
o- 

c 6 

-bo 

o C 

Li 

o- 

o 
o 
m 

s 



o 

o 
f-> 

o 
K 



CLAY RESOURCES AND CERAMIC INDUSTRY 171 

Tho uowly compU'tetl raili'oad connection I'l'oui Alberhill to Corona 
passes Avithin It] miles of the property. The property under lease 
comprises 80 acres, and lies on the east side of the valley, 300 feet 
above its floor. It lias been operated intennittcittly for many years, 
formerly by the now extinct Indei)en(lent Sewer Pipe Co., wiio hauled 
the clay in wagons to the Chase railroad spur, south of Corona, for 
shipment to Tropico. Tt was later under lease to the Alberhill Coal 
and Clay Co.. who did not actively develop the i)i-o])orty, as the com- 
bined transportation costs to Los Aii<i'eles were considerably greater 
tlian from Alberhill, where the principal dei)Osits of this com])any are 
located. 

Development and Mining: A section of the dei)osit, from to]) to 
bottom, as ex])osed by existing: workings, is as foUoAvs : 

Sample Test results 

No. on page Thickness 

Stripping, of sandy soil, with some clay 2-10 feet 

73 323 "Bone" clay, over 35% alumina 4 feet 

71 278 I'ink mottled 16 feet 

72 328 Red, high in iron 2- 4 feet 

70 272 White, known as select Harrington No. 5 7 feet 

69 323 Red Hor.se 40-.50 feet 

The clay beds arc ({uite uniform in ({ualitj^, but varyin"- in thickness 
of individual varieties, over the greater part of 40 of the 80 acres under 
lease. The greatest demand is for the white plastic clay, but the pro- 
duction of this variety is limited by the amount of ])ink mottled that 
can be marketed. The Atlas Fire Brick Comi)any uses the entire out- 
put of the white plastic clay. The other clays are marketed to Los 
Angeles consumers, especially to Gladding, McBean and Company and 
to the Pacific Clay Products Company. 

The i)re.sent (1926-27) mining is being done with a Thew tyjie 0, 
f-yd. gasoline shovel in an 0])en pit about 100 feet square with a 40- to 
50-foot bank. Trucks are used to haul the clay from the floor of the pit 
to a loading bin and chute where it is loaded into larger trucks for the 
seven-mile haul to the railroad. Photo No. 45 is a view of the pit, and 
No. 46 shows the loading chute. 

Considerable ciuantities of clay have been mined in the i)ast from 
0]>en cuts extending along the east side of the i)resent Avorkings, and 
running up the hill with the clay which dii)s about 10° to 15° toward 
the south. There are several tunnels from these pits. To the west, 
about one-quarter mile from the active pit, it is extensive open cut and 
chambor workings from Avhich pink mottled and white plastic clay has 
recently been mined. 

Three to four cars ])er day are being mined and three men are 
employed ;i1 the pit, exclusive of truck drivers. 

Gladding, McBean and Companij. Office of Southern Division at 621 
S. Hope Street, Los Angeles. Through its merger with the Los Angeles 
Pressed Brick Conijiany in 1926, this company now controls important 
clay lands and a clay working plant at Alberhill, in addition to the 
Temescal Tract already owned by the company prior to the merger. 

Alberhill Clay Property. The clay property in which the plant 
is located totals 520 acres, in Sees. 21 and 22, T. 5 S., R. 5 W., as shown 
on plate X by legends L. A. P. B. Co. and L. A. P. Co. This property 
adjoins the Alberhill Coal and Clay Company's property on the east. 



172 



DIVISION OP MINES AND MINING 



The main tunnel pit adjoins the Alberhill company's main tunnel pit, 
and is shown on photos No. 40 and 47. Clay from this pit is loaded by 
hand into side-dump mine cars, and hauled by electric trolley locomo- 
tives across a trestle to the plant on the west side of the railroad, or to 
railroad bins for shipment to the Los Anjreles plants of the company. 
The priiicij^al clay obtained from the pit is main tunnel fireclaj^ which 
is used in the manufacture of fii'e brick. 




Photo No. 46. Loading chute, Emsco Clay Co. (Harrington 
pit). Riverside County. 

About a half mile southwest of the main pit is the Sloan pit, from 
which a number of varieties of clay are produced. A representative 
cross-section of this pit is given by BurchfieP as follows: 



No. of feet 
40 
30 

6 

4 
50 



Strata 
Overburden and j^ellow top clay 
Sloan clay 
Sloan No. 5 clay 
Sloan bone clay (1923) 
Red clay 



' Op. cit., p. 1173. 



CLAY RESOURCES AND CERAMIC INDUSTRY 17o 

This j)it "vvas still an inipoctanl prnduooi- when tlio ])i'()i)orty was 
visited by the author in l!)^.') and l!)2(). The clay was l)('in<i' mined by 
hand methods, and was trans|)orted to the ])lan1 by aulo tnu'i\S. 

Various other pits li;ive been opened u|) l)y the e()m])any. 

Sixteen sam])les I'l-oiii the ))i'0]iei'ly were tested. No. !)() 1o 100, 
inclusive, are i)ractically all Irom the main i)it, and should be com- 
pared with similar varieties from the Alberhill company's property. 
Xo. 101 to lOf), inclu.sive, are from the Sloan pit. For convenience of 
refei-ence, they are ari-an<>'ed in the i'ollowinji' table accordin.<>' to the 
cla\- classilication adopted in this report, which is fully described in 
Cluii)ter IV. 

Sample Record, Gladding, McBean Co., Alberhill Pits. 





Clay 


Clay 








Firefl 


class 


sample 


Page 




Cone 


color 


miiiiber 


number 


reference 


Local nomenclature 


fusion 


White 


1 


91 


260 


Main tunnel sand 


.•!0-31 






103 


260* 


Sloan bone 


3r> 




2 


90 


265 


Main tunnel fireclay 


31 






93 


265 


Select main tunnel 


30-31 




3 


96 


272 


No. 10 


32 






98 


272 


Bone (W-105?) 


35 


Huff 


5 


104 


279* 


No. 5 Sloan 


34-35 




6 


92 


289 


Yellow main tunnel 


28 






97 


290 


Smooth bunker 


31 






102 


290 


Sloan sand 


29 




7 


101 


298 


Sloan white 


30 




9 


94 


311 


West blue 


17 






95 


311 


Select west blue 


18 






99 


312 


Tile 


26-27 


Red 


12 


100 


323 


Yellow stripping 


14 plu 






105 


324 


Sloan red 


18 plu 



* Bur(>hfiel, op. cit.. p. 1174. gives data on No. 5 Sloan, and states that the Sloan 
bone is "iJiactically identically the same as the bone clay No. W-105." He also gives 
data for the yellow top clay from the Sloan pit. 

The total clay production from all of the pits on the company's 
Alberhill property is about 500 tons per day, much of which is .shii)])ed 
to the company's plants in Los Angeles. 

Alberhill Plant. The principal products of the Alberhill ])lant 
are fire brick and other fireclay refractories, face brick, and hollow tile. 
Hand-molded roofing tile is also made. The face brick, fire brick, and 
hollow tile are made by the stift'-mud process, after preparing the clays 
in dry pans. Most grades of fire brick are repressed. Waste-heat 
tunnel driers are used. All ware is fired in round down-draft kilns, of 
which there are twelve, of various sizes from 32 to 38 feet in diameter. 

The plant is well arranged, and well equipped to handle all materials 
in so far as is feasible. 

A well-equipped field laboratory is maintained for the study of raw 
materials and for research on the technical i)roblems arising in the 
l)lant. 

Temescal Tract. This property, totaling 173 acres, is west of the 
Emsco Clay Company's property, 0.4 mile east of the Corona-Elsinore 
highway, and 25-30 feet above the floor of the valley. 

Development. The principal pit i.s 800 feet long, 500 feet wide and 
a maximum of 150 feet high. Red, pink-mottled and blue plastic clays 
have been mined. The varieties were apparently badly mixed, and the 
present exposures in the face of the bank do not offer much encourage- 
ment for expecting a satisfactory supply of uniform material. Some 



174 



DIVISION OP MINES AND MINING 



development work is being done in a tunnel at an elevation about 100 
feet higher than the pit and it is stated that good clays were found 
underlying the Emsco clays. 

At the times of visit, in 1925 and 11)26, the ])it was idh', but was being 
held in reserve for the future. 

/. D. Hoff, of Elsinore, owns a cla}' property in Sec. 22, T. 5 S., R. 
5 W., on which some prospecting has been done, by core-drilling and 




Photo No. 4 7. Gladding, McBean and Company (formerly 
Los Angeles Pressed Brick Company), .A.lberhill, 
Riverside County. Main tunnel pit leased from the 
Alberhill Coal & Clay Company. (See also photos 
No. 40 and 41.) 

test-pitting. A number of samples were sent to the Stanford labora- 
tory by Mr. Hoff, but none of these were large enough to test. The 
general appearance of some of the samples is the same as that of certain 
clays from other properties in the district. Mr. Hoff expects to build 
a clay-working plant near Alberhill in the near future. 

Los Angeles Brick Co. Gustave Larsen, director in charge of opera- 
tions ; Harvey Gardner, plant superintendent at Alberhill. Main office, 
1078 Mission Road, Los Angeles. This company acc^uired the holdings 



CLAY RESOURCES AND CERAMIC INDUSTRY 



175 



of the former California Clay Maiiiifaetnrint: Company in the Alberhill 
district, and built a plant at AlborJiill in ^\)27) for tlie manufacture of 
face brick, fire brick, roofino- file, floor tile, and hollow tile. The manu- 
facture of other products is contemplated by the company. 

The pi-oi)erty at Alberhill consists of the SEj and the E^ SW^ 
Sec. 21, T. 5 S!, R. 5 W., S. B. M., and other nearby property totalinj? 
720 acres. This lies to the west of the principal holdings of the Los 
Angeles Pressed Brick Co. Most of the clays that are being mined at 
]iresent are from the western limb of the synclinal trough in which the 
clays of the district lie. The clays include most of the varieties that 
typify the Alberhill district, and occur in the same irregular fashion, 
without notable continuity of individual strata. There is apparently, 
however, a more extensive dei)osit of high-grade bone clay on this 
property than in any otlier known locality in California. 

Clay Deposits: A numbei- of ])its have been oi)ened on the property, 
but at the time of visit, in July, 1925, and September, 1926, it was not 
])ossible with the data at the writer's disjjosal to definitely establish 
the stratigrai)hic correlations between the various pits, nor between the 
nearby pits of other operators. A number of samples were taken on 
botli occasions. No. 74 to 87, inclusive, were taken in 1925, and No. 229 
to 2:52 inclusive, in 1926. Vertical sections through the "East," 
"West," and "Main" pits are given in the following tables. Photo 
No. 52 shows the East pit as it ap])eared in September, 1926. 



Sample 
No. 



230 



Page 
No. 



300 



Vertical Section, East Pit, Los Angeles Brick Co. 

(From top to bottom.) 

Local name Thioknoss. 

or number Principal uses fi'f t 

Stripping Sometimes for face brick 0-10 

Pink-mottled Face brick, tile ir)-20 

No. 1 red Face brick, tile 10 

No. 9 Fire brick IT) 



Sample 


Page 


No. 


No. 


81 


289 


76 


28S 


77 


27S 


711 


278 


so 


297 



7S 



2S8 



Vertical Section, West Pit, Los Angeles Brick Co. 

(From top to Ixittom.) 

Local name Thickne.ss. 

or number Principal uses feet 

Tile clay Hollow tile, roofing tile 6 

No. 2.') Fire brick and pottery 10 

No. 23 Fire brick and pottery 10 

No. 20 Pressed brick, fire brick 20 

Fireclay Firebrick 10 

Plasti<- pink 

and yellow Fire brick and i)ottery ? 

No. lO' Fire brick 20 



Vertical Section, Main Pit, Los Angeles Brick Co. 

(From top to bottom.) 

Sample Page Local name Thickness, 

No. No. or number Principal uses feet 

S.'') 298 Pink mottled Fire brick, sewer pipe, tile, pottery — Up to 30 ft. 

86 279 No. 26 bone Fire brick 6 

85 298 Pink mottled See above Up to 10 ft. 

83 297 Red clav Hollow tile, roofing tile 12-15 

84 289 P. M. fireclay Fire brick 10-20 

A number of samples were taken from undeveloped or partially 
develoi)ed beds. For convenience, these are given in the following 
table : 



176 DIVISIOX OF MINES AND MINING 

Miscellaneous Samples. Los Angeles Brick Co. 

Thick- 
Sample Page Local name Name of pit from wliicli ness. 
No. No. or number sample was taken Principal uses feet 

74 278 West bone West bone pit Fire brick 4- 6 

75 335 Red No. 2 West bone, underlying Tiie and face 

No. 7 1 brick ? 

87 279 Smooth bone 100 yd. E. of main pit, 

overlving No. 86 Fire brick 15 

232 281 Smooth bone ? ' Fire brick 6 

231 281 High-alumina 

bone ? Fire brick 4 

82 315 Clay shale Blue pit Tile and f a c e 

brick 10-20 

229 300 No. 7 No. 7 pit Fire brick 34 

Note. — Samples No. 231 and 232 were supplied by Mr. Gardiner in Septeml)er, 192(;. 
Name of pit from which sample was taken was not given. 

The areal extent of these various clays can not be definitely deter- 
mined in the absence of core-drilling- data. Enough evidence is at 
hand, however, to warrant the statement that many of the beds are 
practically continuous over areas in excess of -300 acres, although it is 
doubtful if the clay in an individual stratum will be uniform in quality 
over such an area. 

Mining: The clay is mined from the various open pits by hand 
methods and is transported to the plant by auto trucks. 

Plant : Face brick, both plain and ruffled, is the principal product 
of the Alberhill ])lant. Fire brick is being made in increasing amounts, 
and a special high-alumina fire brick is being manufactured from the 
bone clays that occur on the property. Photos No. 48 to 51 show 
various views of the plant, and photo No. 52 is a view of the east pit. 

The clays as they are received from the pits are ground in dry pans, 
and elevated to separate steel bins for each variety of clay. From the 
bins, disc feeders are used to feed an augur machine, which is equipped 
with an automatic cutter. Repressing is applied on ware that requires 
it. A 32-tunnel waste-heat drier operates on a 48-hour cycle. 

Firing is done in four 32-ft. and eight 34-ft. round down-draft kilns, 
fired with air-atomized oil. Buff and cream face brick and all firebrick 
are fired to cone 11, and red face brick are fired to cone 10. Four daj's 
is allowed for firing, four days for cooling, three days for drawing, 
and two days for setting. Each Iciln is therefore fired about twice a 
month. 

One hundred and twenty-five men are employed in the plant, and 
twenty in the pits. 

Pacific Clay Products Company. Robt. Linton, general manager, 
1151 S. Broadway Street, Los Angeles. This company-, which has a 
number of manufacturing plants in Los Angeles County, owns and 
operates several clay proi)erties in Riverside County. The location of 
the properties in the Alberhill-Corona district is shown on plate X, 
page 162. 

Douglas Pit. This is an 80-acre tract consisting of the Ni of NE^ 
Sec. 22, T. 5 S., R. 5 W., S. B. M., adjoining the active pits of the 
Alberhill Coal and Clay Co. on the north. A view of the pit is shown 
in photo No. 53. The pit is mined by hand methods, using shovel and 
wheelbarrow to deliver the clay to small loading chutes for loading the 
trucks which haul it to the railroad bins. 



177 

111(1 llie 
'scribed 
"om top 



11 




uction. 



r^. 



.JjC, 



driers, 



Thickness 
of bed, 
feet 
5 
4 
7 
50-70 



176 DIVISION OF MINES AND MINING 

Miscellaneous Samples. Los Angeles Brick Co. 

Thick - 
Sample Pago Local name Namo of pit from whicli ne.ss. 

No. No. or number sample was taken Principal uses feet 

74 278 West bone West bone iiit Fire brick 4- 6 

75 335 Red No. 2 West bone, underlying Tiie and face 

No. 7 1 brick ? 

87 279 Smooth bone 100 yd. E. of main pit, 

overlying No. 86 Fire brick 15 

232 281 Smooth bone ? Fire brick 6 

231 281 High-alumina 

bone ? Fire brick 4 

82 315 Clay shale Plue pit Tile and face 

brick 10-20 

229 300 No. 7 No. 7 pit Fire l)rick 34 

Note. — Samples No. 231 and 232 were supplied by Mr. Gardiner in September, 192(;. 
Name of pit from which .sample was taken was not given. 

The ureal extent of these various elays can not be definitely deter- 
mined in the absence of core-drilling data. Enough evidence is at 
hand, however, to warrant the statement that many of the beds are 
practically continuous over areas in excess of 300 acres, although it is 
doubtful if the clay in an individual stratum -will be uniform in quality 
over such an area. 

Mining : The clay is mined from the various open pits by hand 
methods and is transported to the plant b}^ auto trucks. 

Plant .- Face brick, both plain and ruffled, is the principal product 
of the Alberhill ]ilant. Fire brick is being made in increasing amounts, 
and a special high-alumina fire briclv is being manufactured from the 
bone clays that occur on the property. Photos No. 48 to 51 show 
various views of the plant, and photo No. 52 is a view of the east pit. 

The clays as they are received from the pits are ground in dry pans, 
and elevated to separate steel bins for each variety of clay. From the 
bins, disc feeders are used to feed an augur machine, which is equipped 
with an automatic cutter. Repressing is applied on ware that requires 
it. A 32-tunnel waste-heat drier operates on a 48-hour cycle. 

Firing is done in four 32-ft. and eight 34-ft. round down-draft kilns, 
fired with air-atomized oil. Buft" and cream face brick and all firebrick 
are fired to cone 11, and red face brick are tired to cone 10. Four days 
is allowed for firing, four daj^s for cooling, three days for drawing, 
and two days for setting. Each kiln is therefore fired about twice a 
month. 

One hundred and twenty-five men are employed in the plant, and 
twenty in the pits. 

Pacific Clay Products Coinpany. Robt. Linton, general manager, 
1151 S. Broadway Street, Los Angeles. This company, which has a 
number of manufacturing plants in Los Angeles County, owns and 
operates several clay properties in Riverside County. The location of 
the properties in the Alberhill-Corona district is shown on plate X, 
page 162. 

Douglas Pit. This is an 80-acre tract consisting of the N^ of NE^ 
Sec. 22, T. 5 S., R. 5 W., S. B. M., adjoining the active pits of the 
Alberhill Coal and Clay Co. on the north. A view of the pit is shown 
in photo No. 53. The pit is mined by hand methods, using shovel and 
wheelbarrow to deliver the clay to small loading chutes for loading the 
trucks which haul it to the railroad bins. 




al view of AlbeihiU plant, L<.s Angeles Brick Company. (Plioto by cuuile-sy uf the coinpanjj 



176 

IV 



Sample 
No. 


Page 
No. 


74 
75 


278 
335 


87 


279 


232 
231 


281 
281 


82 


315 


229 


300 


Note.- 
Name of 


-Sample.= 
pit from 



The areal ex 
mined in the 
hand, hoAvever 
practically con 
doubtful if the 
over such an a 

Mining: Th 
methods and ii 

Plant: Fac 
of the Alberhi 
and a special 
bone clays th; 
various views 

The clays as 
and elevated t 
bins, disc feed 
with an autora 
it. A 32-tuni 

Firing is dc 
fired with air- 
are fired to CO 
is allowed foi 
and two days 
month. 

One hundn 
twenty in the 

Pacific Cla 
1151 S. Broa 
number of n 
operates sevei 
the propertie 
])age 162. 

Douglas P 
Sec. 22, T. 5 
Alberhill Co£ 
in photo No. 
wheelbarrow 
trucks which 



f'LAY RESOURCES AND CERAMIC INDUSTRY 



177 



The clays are similar to those on the adjoining Alberhill and the 
Gla(hlin^', MeBean properties. Pour samples were taken, as described 
in the foHowiiijr tab)*', wliich is arranged as a vertical section from top 
to bottom oi' the known ileposits: 




Photo No. 49. Los Angeles Brick Company, Alberhill plant, during construction. 

Riverside County. 




Photo No. 50. Los Angeles Brick Company, Alberhill plant, tunnel driers, 
during construction. Riverside County. 



Sample 
number 


Page 
reference 


Clay 
class 
number* 


Local nomenclature 


Thickness 
of bed, 
feet 


108 
109 
110 
111 


290 
266 
298 
315 


6 
> 

7 
10 


Upper Douglas 
Douglas main tunnel 
Douglas 
Lower Douglas 


5 
4 

7 
50-70 


* Refers t 


o clay classificat 


ion, described 


fully in Chapter IV. 





12 — 54979 



178 



DIVISION OF MINES AND MINING 



Hoist Pit. Tliis is a 40-aere property, consisting of the NE^ of NE:^ 
Sec. 26, T. f) S., K. 5 W., and lies soutlieast of the active workings of the 
Alberhill company. The principal varieties of clay exposed in this pit 
are known as Hoist Pit blue (sample No. 112, p. 324) and Hoist Pit 




Photo No. 51. Lo.s Angeles Brick Company, Alberhill plant, 
showing' drier cars and brick represses. Riverside County. 



red (sample No. 113, p. 324). The blue clay is about 40 feet thick and 
overlies the red clay, which is about the same thickness. Both varieties 
are red-burning plastic clays, of particular value in the manufacture of 
sewer-pipe. 



CLAY RESOURCES AND CERAMIC INDUSTRY 



179 



McKnicht Clay Pit. The ]MeKniy:]it clay i)it, :^5 miles by road 
soiitlnvest of Corona, liiverside Connly, in Sees. ;>, I) and 10. T. 4 S., 
R. 7 W.. S. T>. il., has been known and worked for over :{() years. 

Description of Dejiosit and "\Vorkin<is. The dei)osit is composed of 
two typical varieties of clay ; an ui)i)er bed, 60 feet thick, of red- 
burning plastic clay, used in the manufacture of sewer pipe, electric 
conduit, and hollow building tile, and a lower bed of fire clay, 30 feet 
thick, used for fire brick and flue lining. The sewer-pipe clay is repre- 
sented by sample No. GG, i)age 277, and the fireclay by sami)le No. 67, 
page 277. From 2 to 4 feet of stripping overlies the clay beds. 

The present workings attack the clay beds from exposures on the 
northerly side of a steep hill, into which the clay dips at an angle of 
a|)])roximately 35°. The fire clay is mined through a lower tunnel, 
410 feet long, having its portal 500 feet east of an upper tunnel and 








,f* 






u^.*^<^ 



y '-.-*f. «*' 



■«"-■' 



Photo No. 52. East pit, Los Angeles Brick Co., Alberhill, Riverside County. 

70 feet lower in elevation. The two tunnels are connected by a raise, 
and clay is mined by room and ])illar methods, dumped into the raise, 
and drawn off into small mine cars in the lower tunnel. The rooms in 
which the fire clay is mined are about 15 feet high, and connect with 
an open pit and tunnel at a still higher level from which the red sewer 
pipe clay is being mined. P^xtensive workings of a similar character, 
especially to the southeast, attest the active mining of this deposit over 
a long period of years. The southeastern portion of the deposit has 
been exhausted. It is known that the fire clay pinches out to the west- 
ward, but there is apparently a good tonnage of the sewer-pipe clay 
remaining. 

All mining and loading is hy hand methods. Each of the two work- 
ing levels is equipped with a bin for receiving the clay from small mine 
ears and storing it for the light truck which is used for hauling 1.7 
miles to a siding ^^n the southeastern edge of Corona. At the time of 
visit, July 16, 1925, the output was 50 tons per day, of each clay. 



180 



DIVISION OP MINES AND MINING 



WiLDOMAR Kaolin Deposit. ''iMie Pacific Cbiy Products Coinjjany 
owns a deposit of non-plastic, (|iiartzose, whito-bunrm^' kaolin located 
^ mile east of the Inbuul Highway, fi-oni a jioint 2.(i miles southeast of 
Wildonuir. The ])roperty comprises 18 acres, in It. 'A W., T. 7 S., 
S. B. M. 

The material has been exposed by stripping- in two places, about 
150 feet apart. It lies in a bed from 80 to 42 inches thick dipping 30° 
west, forming tlie side slo])e of a low hill that rises above the valley 
floor. The southerly exposure is 100 feet long, and has been mined 




Photo No. 53. Douglas pit, Pacific Clay l^rocUicts Comisany 
at Alberhill, Riverside County. 

for 50 to 60 feet above the valley, and for a length of 50 feet. A shaft 
has been sunk to follow the bed beneath the valley floor. Access to the 
shaft was not convenient at the time of visit on July 21, 1925. The 
northern exposure is 70 feet long by 50 feet wide, and about half of 
the exposed material has been mined. 

A thin layer of debris overlies the deposit, so that tracing beyond the 
stripped exposures is not possible without excavation or boring. 

^Miscellaneous Properties. The company also owns the following 
j)roperties in the Alberhill district : Quintet, consisting of 88.79 acres, 



CLAY KESOUKl'ES AND C'EKA.MU l.NDUSTHV 181 

ill tlie W.', XWj Sec. 26, and El Sobrantc, 160 acres, coinprisinu: the 
XEi Sec. '26, both in T. 4 S., R. 6 W. ; Tenicscal Sixtv, 60 acres/ com- 
prising the \W1 NW] and Ni NEj XW] S(>c. 12. T. 5 S., R. 6 W. ; 
Terra Cotta Ei<rhty, HO acres, comprising- the Wi SW{ Sec. 26, and 
Terra Cotta Plant Site, 40 acres, comi)risino: the NE^ SW^ See. 26, in 
T. 5 S., R. 5 W. Ill addition, the company owns a lialf interest with 
GladdinjTr, McDcaii and ("omijanv in the Elsinore Joint Proijcrty, 120 
acres, comprising; the W^ NE^ and the SE{ NEj Sec. 26, T. 5 S., R. 
5 W. Little or no development work has been done on these i)roperties. 

Hancoch's Brick Yair].^ C. V. Hancock and Son, owners. l.'?.'}0 Lemon 
Street, Riverside. This yard, for the mannfaeture of common red 
brick only, is located on the southern outskirts of the city of Riverside. 
Clay is mined with a steam shovel from a 10- to 20-foot bank of red clay 
near llie plant. The brick are molded by Ili(> stiff'-mud ])r()cess, and 
fii'ed in jias-tired field kilns. The capacity of the plant is 4o,000 brick 
per day. The len<>th of the operating season tlepends upon local 
demand. Twenty men are employed. 

Prado Tile Company. Losse and Romedas, owners. At Prado, two 
miles west of Corona. This is a i)lant for manufacturing hand-made 
roofing tile and Jlexican pottery. The clay is mined from a local deposit 
and is ])ugged by treading. The ware is di'ied in air. and is fired in 
an oil-fired, rectangular up-draft kiln, holding about 1000 tile (4 
.squares of 100 square feet). About 10 men are employed at the plant 
when operating. The price of the tile, at the i)lant, was $17 ])er 
square in 1926. 

Temescal Water Company. ( i) A small i)it in ])ink-mottled clay 
was opened up during the season of 1926 on a projierty in Sec. 35, T. 
4 S., R. 6 W., about a mile southwest of the Emsco pit. The ownership 
of the property could not be determined, as no work was being done at 
the time of visit, in Se])tember, 1926. It is said to belong to the 
Temescal Water Comi)any, and that it was being develoi)ed by 'Doc' 
Meyers. The pil had lieen ojiened by an o])en cut, 25 feet wide and 40 
feet long. A horse scrajier was used for removing overburden, and the 
clay was mined by hand methods. The only clay exi)osed was ]iink 
mottled, a sample of which was taken. See No. 218, ])age .'529. The 
extent of the deposit could not be determined, but the clay could be 
traced around tlx^ liill for a distance of about 200 yards. 

J. W. Wilson of Vidal, a station on the Parker cut-off of the Santa 
Fe Railroad, in San Bernardino County, has located 26 claims on an 
extensive clay deposit in a playa three miles by road .south of Vidal in 
Riverside County. 

The clay varies in color from nearly white to pinki.sh and blue-grey. 
The beds have a total thickness of at least 20 feet over the entire area, 
excei)t where recent erosion has removed portions of the deposit. In 
many places, however, thin beds of unconsolidated sandstone, from 
less than inch to .several inches in thickness, are interbedded with clay 
beds from one to three feet in thickness. The sandstone beds contain 
many poorly i)reserved fossils. notal)ly sharks teeth, and small clam 
shells less than an inch in diameter. The clav beds are overlain by 
varying thicknesses of loosely consolidated sand and fine gravel, but 

» Supplemented by data obtained by W. B. Tucker, November, 1927. 



182 DIVISION OF MINES AND MINING 

there are large areas where erosion has removed practically all of this 
capping, and has exposed the clay beds. 

Samples No. 42 and 43 were taken for test. The results, given on 
])age :U0, indicate that tlie clay is unsuited for general ceramic pur- 
poses, although its extremely fine grain, and high plasticity, may indi- 
cate certain special uses. 

Bibl (Clay resources of Riverside Countv) : State ]\Iining Bureau 
Bull. 38, pp. 221-224 and 252-253; Prel. Kept. 7, pp. 74-91. 
Kept. XV, pp. 559-574; XIX, pp. 185-219. Also Jour. Amer. 
Cer. Soc, Vol. 6, pp. 1167-1175, 1923. 

SACRAMENTO COUNTY. 
(By C. A. Logan and W. F. Dietrich.)' 
General Features. 

Sacramento County is almo.st in the geographic center of the state, 
and lies principally in the Great Central Valley, with the eastern 
])art of the county rising into the foothills of the Sierra Nevada Moun- 
tains. The elevation varies from 30 feet above sea level at Sacra- 
mento (Southern Pacific depot) to about 900 feet above the sea on the 
east side of the foothills. The Sacramento and American rivers unite 
just northwest of Sacramento city limits, the former flowing south and 
forming the western county line. Cosumnes River traverses the south- 
eastern part of the county, flowing into Mokelumne River on the 
southern county line. 

The county and capital city are served by two transcontinental rail- 
ways, the Western Pacific and Southern Pacific, which cross the county 
from north to south. The Central California Traction Company's line 
from Sacramento to Stockton connects with the Santa Fe system, 
and the San Francisco-Sacramento electric railway runs southwest 
to Oakland and San Francisco. A third electric interurban line, the 
Sacramento Nortliern, run.s north as far as Chico. Three regular 
steamer lines ply between Sacramento and San Francisco on the river, 
giving freight and passenger service, besides which there are numerous 
other river cargo carriers. Two large power companies. Pacific Gas and 
Electric Company and Great Westcn-n Power Company, supply electric 
power, and the former company and Sacramento Gas Company supply 
gas. Transportation and power needs are thus well supplied. State 
highways radiate in all directions from Sacramento. 

Sacramento County has been an important gold-producing district 
for a long time. Previous to the enactment of the anti-debris laws 
there was considerable hydraulic mining in the Folsom district and 
the gold production from this source and from drift mining was as 
high as half a million dollars a year. In 1899 gold dredging began and 
gold production reached its peak between 1909 and 1919, the maximum 
yield being over two and a half million dollars in 1919. From now on, 
production from the gold dredges will decline rather rapidly. 



' Ml-. T.i()Kan'.s report on Sacramento t'uunty \va.s made in 1925. See State Min- 
eralogist's Report XXI, pi>. 1-22. Mr. Dietrich visited some of tlie clay plants in the 
county iti 1925 and 192ii and has added certain details to Mr. Logan's descrijitions, 
especiall.v to that referring to the Natoma Clay ComiJany. He also added notes on 
the Michigan Bar clay deposits. In 1927. Mr. Logan visited the plant of the Valley 
Brick Company, and supplied the description that is included here. 



CLAY RESOURCES AND CERAMIC INDUSTRY 183 

As a hy-jiroduct industry, ntiliziup' tho waste rock ])iles of the 
(Ired^red laud, tlie roek-cfusliino- industry has become important and has 
jrrown rapidly with the increased use of concrete. Sand and gravel are 
also dredged in large quantities from the American River bed. 

Brick, tile, and a great variety of clay products are produced, using 
local clay mostly. Natural ga.s is supplied for domestic use. in part 
from wells. Granite is quarried, and ])latinum metals and silver are 
recovered as by-products of dredging. 

Clay Resources. 

A few deposits of high-grade clay occur in the southeastern part of 
the county, adjoining Amador County. These are part of the lone 
formation, which is so productive of clays in the vicinity of lone. Tlie 
deposits were worked a number of years ago, and were the basis for 
establishing one of the first clay-working plants in California, but have 
been idle for many years, and present exposures are insufficient to 
warrant development", in view of the lack of cheap transportation 
facilities in this area. 

There are adequate supi)lies of common clay in the county, suitable 
for the manufacture of red structural ware. The gold-dredge silt now 
being mined by the Natoma Clay Company is of particular interest. 
The proximity to the important de]iosits of high-grade clays of Lincoln, 
Placer County, and lone. Amador County, has encouraged the estab- 
lishment of a number of clay plants in or near Sacramento. 

Cannon and Company (formerly Sacramento Clay Products Com- 
pany). Owner, Cannon and Company, a close corporation. D. A. Can- 
non, president and general manager. IMain office. 400 Forum Building, 
Sacramento. The plant and clay beds are at Ben Ali siding, four 
miles from Sacramento, on what was formerly a part of Rancho del 
Paso, adjoining the Southern Pacific main line and state highway. 
There are about two hundred acres in the holdings. A view of the 
plant is shown on photo No. 54. 

About sixtv per cent of the clay used in the plant is mined on the 
property. White clay and sand are brought from Lincoln and lone 
deposits for making fire brick and are mixed in desired projiortions 
with the local clay for making other products. 

The clay on the property is a firmly consolidated yellowish-brown 
sandy clay, red-burning, and locally called 'hardpan.' It is covered 
by alayer of reddish sandy loam, which is worked and marketed sepa- 
rately for molding sand. The 'hardpan' layer varies in thickness but 
the entire bank is similar in quality, and is worked to a depth of fifteen 
to twenty feet. 

Clay is dug by a steam shovel and horse scrapers, loaded in cars and 
hoisted to the plant, where it is dumped and aged under cover. It is 
fed by an auger feed to two dry pans for grinding, after which a 
bucket elevator lifts it to a Hum-Mer electric screen, screening to the 
desired size dei)ending on the ])roduct to be made. The clay then 
passes to storage biiis, pug-mills, and brick or tile machines. The stiff- 
mud i)rocess is used. The pr(»ducts manufactured iiiclude face brick, 
interlocking and hollow tile, fii-e brick, hollow tile, Roman brick and 
other special shapes and sizes. The shrinkage of the local clay is one 
in thirteen, which is low comi)ared with the Avhite clays used, and 



184 



DIVISION OP MINES AND MINING 




CLAY RESOURCES AM) CERAMIC INDUSTRY 1 So 

shrinkajre of different ])ro(luc*ts varies -with iiroiiortiniis of the elays 
employed. Fusibility of the fire briek is above :W(W Fahrenheit and 
the face briek 2100 to 2200- Fahreidieit. P'or burninfr the brick and 
tile there are five down-draft round kilns, each with a capacity of 
70,000 to 80.000 bricks. The bricks are burned five days and tile two 
and one-half to three days. Clay workinp- machinery is o])erated from 
a main drive, usinji- a 20()-h.p. electric motor, and crude oil fuel is used 
for the kilns and steam shovel. There is a spur track to the plant from 
the railroad main line. Tliirty-five to forty men are emi)loyed and tlic 
jdant has a cai)aeity of 10,000 to 12.000 tons a month. 

Interlocking' tile is used for bearing walls. This tile and the face 
brick have been used in the new California State Life Building and in 
other large buildings recently erected in Sacramento. 

Bibl: State Mineralogist's Reports XV, ]). 404; XXT, p. 7. 

Michigan liar Claij Deposits. In the vicinity of ^Michigan Bar. 6..") 
miles north of Carbondale, are a number of exi)Osures of clay belonging 
to the lone formation. Attempts have been made at various times to 
develop these deposits, but on account of the distance from railroad 
transportation and the lack of large exposures of uniformly high-grade 
clay, no recent commercial production has been attained. Tiie most 
l)romising showings are in Sec. 2, T. 7 X., R. 8 E., :\I. D. :\1., on the 
south side of Cosumnes River, 2 miles east of Bridge House. Van 
Vleck and Sons of ^Michigan Bar own the north half of the section, as 
well as large acreages to the south and ea.st, some of which may 
cover deposits of future value. Geo. Cutter of Sacramento owns the 
XEj of the SE{ of the section; C. E. Bundock of ^Michigan Bar owns 
the S^ of the NW-^ of the SEj- of the section. The ownership of the 
remaining portions of the section was not determined. 

Portions of the area investigated were formerly the scene of hydraulic 
gold mining operations, especially near the eastern .side of the section, 
and extending over i)arts of section 1. Gravel still remains over por- 
tions of the area, in jilaces to a dei)th of 20 feet. On the Geo. Cutter 
pro])erty, hydraulic mining has ex])osed a bed of white plastic clay 
(sample Xo. 143), underlying the remnants of gravel at that point. 
The clay bed has a dip of 7' west, following the slope of the hill. The 
total expo.sed thickness of clay is as much as 20 feet in ])laces, l)ut it 
was not possible to find a continuous and uniform stratum of clay 
that is not seriously contaminated with a network of hard, weather- 
resisting stringers of siliceous limonite. The erosion in the 45 to 50 
years since hydraulic mining days has left the iron-bearing stringers 
in shar]) relief on the ex])osed clay beds. At one point, near the 
center of the Cutter property, the clay is not greatly contaminated 
over an area about 50 feet square, and for a thickness of three to 
four feet. A sample, Xo. 148, was taken from this exjiosure, in order 
to indicate the ])Ossible utility of clay of such (piality, if it could be 
found in sufficient abundance. The test results are given on page 274. 

Just north of the Geo. Cutter property, on the eastern portion of the 
Van Vleck land, a stream hnuk affords a good exposure of a fine-grained, 
white- to cream- and but^'-burning clay. The expo.sed thickness of the 
bed varies from :] to 6 feet, extends for 200 feet in length, and can be 
traced in cro.ss-gullies for at least 100 feet back from the bank of the 
stream. This bed apparently underlies the clay exposed in the gravel 



186 DIVISION OF MINES AND MINING 

pits. 8am])le No. 144 was taken for te.stinf?, the resvilts of whicli are 
•i'iveii on jiaye 27;}. 

It is entirely possible that prosi)ect drilling over this area, and in 
adjoining properties, might disclose clay dei)Osits of commercial import- 
ance, but in view of the minimum truck haul of 6.5 miles to Carbondale, 
or 12 miles to the Western Pacific Railroad in the Sacramento Valley, 
it is unlikely that serious work will be done until some time in the 
future. 

Muddox Pottery. H. C. INIuddox Company, owner; H. C. Muddox, 
president. Office and plant at Thirtieth and L streets, Sacramento. 

This company operates a ]ilant for the manufacture of sewer pipe 
and chimney ware. They own some land at Carbondale, Amador 
County, where they dig clay, and also buy some common clay locally. 

Bibl: State Mineralogist's Report XXI, p. 10. 

Natoma Clay Company. This company was organized to produce 
clay from the settling basins that have resulted from gold dredging 
operations in the Natoma dredging area. The clay consists of the fine 
clay and silt that is carried by the reject M'ater from the dredge ponds. 
This water is passed into shallow basins which were previousl}- formed 
by the dredge, and the clay and silt are completely settled before the 
water is returned to the main stream. During the years of dredge 
operation in this district, many millions of tons of clay have been 
artificially produced in this fashion. The individual basins are trough- 
.shaped, and are generally less than 30 feet deep, ranging from 75 to 100 
feet wide at the surface. The sides of the troughs are formed by 
boulder piles on an angle of repose of approximately 45°, or by vertical 
banks of unmined gravel. Some of the basins are one and a half 
miles or more in length. Much of the clay area has been prosi)ected 
by hand-augers, and in one summer's prospecting alone, over 6,500,000 
tons were proved. 

The clay is extremely fine grained, yet contains a sufficient proi)or- 
tion of non-plastic matter to impart desirable ceramic pro])erties to 
the mass. The proportion of non-plastic matter, and the fineness of 
grain varies from place to place, but in any given basin there is a 
remarkably uniform gradation from top to bottom, with the finer 
material nearer the surface, making it possible to mine two or three 
different grades of material. 

Many laboratory and full-scale tests have been made on the clay, 
and it has been found to be jiarticularly useful where an excellent 
range of dark-red colors and a fine even texture is desired. High dry 
.strength, and a long vitrification range, coupled with very low porosity 
when vitrified, have been thoroughly demonstrated. For the results 
of tests by the writer on two different samples, see No. 210 and 212, 
I)age 387."^ 

Mining operations were started in the summer of 1926, on the Alder 
(Jreek pit, half a mile from a spur track of the Southern Pacific Co., 
and one and a half miles south of Natoma. The clay is mined by an 
Tnsley 10-ton gasoline shovel, loading into contractor's dump cars 
on a narrow-gauge track. See ])h()to No. 55. Haulage to llie loading 
bins at the siding is done with a gasoline locomotive. 

Bibl: State Mineralogist's Report XXI, p. 3. 



CLAY RESOURCES AND CERAMIC INDUSTRY 



187 



Panama Pottery. Owner, Panama Pottery Company, Inc., a close 
corporation. Victor Axclson, president ; Andres Anderson and Gustav 
fJohanson, principal owners. Address, post office box 797, Sacramento. 
The plant is jnst sonth of Sacramento city limits near Twentj'-first 
Street road. See photo No. 56. 




Photo No. 55. Electric shovel in preliminary cut. Natoma Clay Co., at Natoma, 

Sacramento County. 




Photo No. 56. Panama Pottery Company's plant, near Twenty-first Street road, 
just south of Sacramento. (Fi-om State Mineralogist's Report XXI, p. 8, 
1!(25.) 

This company owns no ehiy deposits at ]iresent, bnt buys red-burn- 
ino: clay locally and white clay from Lincoln and lone. The products 
of the plant are houshold stoneware, including jars, water coolers and 
filters, jugs, mixing bowls, pitchers, etc. Fancy garden pottery and 



188 



DIVISION OF MINES AND MINING 



common and fancy flower pots are also produced. Tlie company has 
patented a new one-])iece mold for embossed flower pots and are 
exclusive makers of this line which is made from cream-burning clays. 
See photo No. 57. 

Clay for the various products is crushed in a dry pan and elevated 
to a ;30-mesh shalving screen. It is then tempered and run throuf»'h the 
pug mills, aged and run through the pug mill again. After molding, 
it stands for a short time on shelves and is taken thence to the dryer. 
White ware is burned 48 to 52 hours at a temperature of 2200 degrees 
Fahrenheit, and red ware 87 to 42 hours at a temperature of 1800 
degrees Fahrenheit. 

Eciuipraent at the plant includes two pug mills, a dry i)an, glaze 
grinder, one flower-])ot machine, three jolly wheels, shaking screen, and 
two down-draft kilns with a total capacity of 16,000 gallons of stone- 
ware. Crude oil is used for flriiig the kilns, and electricity for power. 





■*ii 


A 


'♦f 


" 1 




Kl^ 




1 

• 1 


w. 




. . M 


- 






i 


a 




M4MJ 


fit. 


r 1 






^^^ 


SM' 




E 1 


i 


wd 


^^ 


i 


-*»-^' : 1 


^ 




1 






1 




1 




"tT^^^t!' ' 


^-.^=ji>«.'-' ■ -2, 


•• i-- 


mi ■§ 


'^'■•'i'W'fcJ* • 


»u 


•4 : ■• ' 




i^Hl 


1 






JW 


-m 




•If 


mtry 


i 






k 




.■^■^lie* 











Photo No. 57. Fancy garden pottery, manufactured by Panama Pottery Com- 
pany, Sacramento. (From State Mineralogist's Report XXI, p. 8, 1925.) 

Sixteen men are employed. About ten days are required for a com- 
plete run, from setting to the time of drawing. The market for the 
goods is mostly in central California and deliveries are nearly all by 
automobile truck. 

Bibl: State IMineralogi.st's Report XXI, ]). 7. 

Sacramento Ilrivk Compani) (formerly Biverside Brick Yard). This 
is a .stock comi)any, subsidiary to Sacramento Navigation Com])any. 
W. P. Dwyer, i)resident ; A. J. Foster, general manager; H. K. John- 
son, secretary. JNIain office, Front and N streets, Sacramento. The brick 
plant is three miles south of the Sacramento city limits, near Sacra- 
mento River. 

The company makes common brick exclusively. The deposit is clay, 
sjind, and loam, with no hnrdpan, and is worked about 16 feet deep by 



CLAY RESOURCES AND CERA^flC INDUSTRY 189 

51 steam sliovel and draf^-liiio scraper. Clay is loaded into four-ton 
side dump ears and hauled in trains by dinkey locomotives to the plant, 
Avliere it is (hnnpcd into I'olls. elevated to the pu^- mill and temi)ered. 
It passes thence to a soft-mud hi'ick machine where bricks are pressed 
and dusted with ground red gro<r from an outside grog grinder and 
storage bin. From the brick machine the bricks ])ass by -wire cableway 
to steam-rack dryers, Avhere they are dried in about 18 hours. They 
are then burned in open-draft field kilns for seven days at a temperature 
of 1700° to 1750° P'ahrenheit. The kilns contain from 400,000 to 
500,000 bricks each. The shrinkage in burning is about 6% . The plant 
has a daily capacity of (JO. 000 bricks and em])Ioys a crew of sixty men. 
Crude oil is used for burning bricks, for the steam .shovel and loco- 
motives, and electric i)Ower is used for oi)erating machinery. The 
direct operation of the brick machine retpiires only three or four men. 
The company has another i)lant between the present site of operation 
and the river, but this has been abandoned. It was formerly operated 
at a daily capacity of 125,000 bricks during the dry season only, but 
the present operations are carried on steadily. 

Bibl: State Mineralogist's Reports XV, p. 403; XXI, p. 9. 

Valley Brick Compan!). 'Shun office, 809 J Street, Sacramento. Plant 
two miles southeast of Sacramento city limits, near S. P. and Central 
California Traction Company lines to Stockton. H. J. McClatchy, 
lu-esident ; A. :\I. Weston, secretary ; II. F. Goss, plant superintendent. 

The proi)erty includes 40 acres of clay land and equipment for mak- 
ing common red brick. The deposit has an average depth of 20 to 22 
feet, of which the upper 12 feet is yellowish-brown clay and the balance 
sandy clay. Near the surface, and covered by only a thin layer of 
loam, occurs about two feet of 'hardpan,' which is tight and difficult to 
dig. Clay is dug with an Erie shovel and loaded on cars which are 
hoisted up an incline to the grinding Hoor. After grinding the clay is 
.stored in a bin. Rolls, previously used for grinding, are being replaced 
now by two 9-ft. di-y pans. The stiff'-mud jirocess is used, emi)loying a 
Freise auger machine, and wire cutter. Green brick are dried six to 
eight days. 

Field kilns of up-draft tyi)e, containing about 180,000 brick each and 
using for fuel crude oil which has been atomized by air under 80 pounds 
pressure, have been in use heretofore. Brick was water smoked for three 
days and burned three days thereafter, reaching a maximum tempera- 
ture of 1750° during the latter half of the burning. Eight Funnan 
kilns, with a cajiacity of 600,000 brick each, will be built soon, and the 
other changes will increase the brick-making cai)acity from 42,000 to 
63,000 daily. The sea.son for digging clay and making brick extends 
from April to Xovembei-. A new steam plant of 30()-li.]). capacity is 
being built, and .steam will be substituted for air to atomize the fuel oil. 
During the busy .season 30 men are employed. 

Bibl (Clav resources of Sacramento County) : State Min. Bur. 
Bull. 38, pp. 225-226 and 253; Prel. Rept. 7, i). 91 ; Rept. XXI, 
pp. 2-10. 



190 DTVIRIOX OP MINES AND MINING 

SAN BENITO COUNTY. 
(By C. McK. LiAizntE and W. F. Dietrich.)' 
General Features. 

San Benito is one of the central counties situated between Monterey, 
a coast county, which adjoins it on the south and west, and ^Merced and 
Fresno, two of the great San Joaquin Valley counties, whieli bound it 
on the northeast. Santa Clara County and a corner of Santa Cruz 
adjoin it on the north. 

The county extends southeasterly from Pajaro River for 70 miles 
with an average width of 20 miles. Its area is 1392 square miles and 
the population, most of whom reside in or near the few towns along the 
railroad in the northern part, is 8995 (1920 census). 

About one-fourth of the county is government land. Most of the 
remainder was long held in the form of large land grants and immense 
ranclios. As may be expected, cattle-raising early became an important 
industry and it still is of prime importance. In later years some of 
these ranchos have evolved into fruit orchards and small farms, due to 
irrigation and intensive cultivation of the valley lands. As a result, 
fruits and vegetables, dairy and poultry products, as well as hay, grain, 
and live stock, have become imi)ortant sources of wealth. ^Mining has 
been carried on since 1858, the total recorded mineral production to 
date approximating $30,000,000. 

Transportation facilities are limited. There is a branch of the 
Southern Pacific railroad from Gilroy, via llollister, the county seat, 
to Tres Pinos. The main coast line of the Southern Pacific also touches 
the county at Logan, after passing through Pajaro Gap. The ' Califor- 
nia Central,' a line 8 miles in length, connects the Old ^Mission Port- 
land Cement Company's plant with the Southern Pacific at Chittenden. 
Other parts of the county are served by auto stages from Holli.ster and 
Tres Pinos. The southern section can be reached equally as Avell 
through Coalinga or Mendota on the San Joaquin Valley side or from 
King City and San Lucas on the west. Excellent highwaj^s join Hollis- 
ter with Merced on the valley highway route and with San Juan Bau- 
tista on the coast route of the highway system. The road to the interior 
is by way of Paeheco Pass. 

The famous Santa Clara Valley penetrates the northern end of the 
county as far as Hollister. From this point the narrow valley of San 
Benito River continues southeasterly to the southern boundary. This 
river and its chief tributary, Tres Pinos Creek, with many smaller 
streams flowing in from east and west practically drain the entire area. 
Numerous smaller mountain valleys are found along the flanks of the 
two ranges of the Coast system, which roughly parallel one another and 
dominate the topography. 

Geology. 

There is considerable literature on the geology of portions of San 
Benito County, but most of the detailed geologic studies have been 

' Mr. Laizure studied the mineral resources of this county in 1926. See State 
Mineralogist's Report XXII. pp. 217-247. His general description of the county and 
his notes on the clay resources were revised for the purposes of the present report by 
Mr. Dietrich, who visited the county in August, 1925, and made an unsuccessful 
attempt to find some of the deposits of high-grade clay that had been previously 
reported. Mr. Dietrich also added notes on the deposit at Paicines. 



CLAY RESOURCES AND CERAMIC INDUSTRY 191 

confined to those sections considered to be possible oil-bearing territory 
or to the quicksilver iiiininy: districts, and no single geologic report fully 
cover.s the county. 

The general geology as shown on the geologic map of California pub- 
lished by the «tate Mining Bureau in ll)l(i is briefly outlined in the 
following paragraphs. 

The Gavilan Range on the western side is composed of ancient granitic 
rocks associated with crystalline schists and limestones. Dolomite and 
more rarely barite deposits occur with tlie limestone and have been 
developed from San Juan Bautista southerly to Cienaga Valley. 
Farther south in a snuUl area surrounding the Pinnacles National 
Monument, which in itself is an example of intense vulcanism, fine- 
grained volcanic rocks occur. In the southwestern portion of the 
county, from To])o Valley south and east to iSan Benito lliver, the 
formations exposetl are sedimentary rocks of Tertiary age, which include 
numerous gypsum beds, some bituminous sandstones and diatomaceous 
earth. 

On the northeastern side of the river the Diablo Range rises abruptly, 
and from near Hernandez south and east beyond San Carlos Peak it is 
made up of Franciscan rocks, chiefly serpentine but with much red 
chert, sandstone, slate and schist near the river. From Idria north- 
westerly nearly to Llanada, Cretaceous and Tertiary rocks make up the 
main range. From Llanada northward to the northern end of the 
county the Diablo Range is typical of the Coast IMountains, consisting 
of serpentine, chert, metamorphic sandstone, slate and schist. Quater- 
nary and late Tertiary sediments comprise the valley area surrounding 
Ilollister, and sandstone, shales, sands, gravels and clays are much in 
evidence along San Benito River as far south as Hernandez. 

San Andreas fault, a dominant structural feature of the geology, 
enters the county near Chittenden and runs southeasterly along San 
Benito River as far as the town of San Benito. From here it crosses 
a low divide into Rabbit Valley, and from there it follows Bitterwater 
Creek to its junction with Lewis Creek and then continues southward 
up Lewis Creek. 

An extensive and diversified number of mineral substances are found 
in San Benito County. Both metallic and nonmetallic minerals are 
inckided in its resources, but commercial production has been limited 
and many deposits have remained entirely undeveloped on account of 
their distance from railroad transportation. Neglect of mining opjwr- 
tunities may also be due in part to the fact that many deposits are on 
l^rivate lands, whose owners are interested in other lines of activity. 

Quicksilver production has given San Benito its reputation in the 
mining world, as it ranks among the oldest and most important quick- 
silver producing counties. The New Idria mine, in the southern part, 
is the largest single producer of quicksilver in the state. Since 1918, 
however, the value of the county's annual output of quicksilver has 
been exceeded by that of cement. Crushed rock production closely 
follows quicksilver in annual value of output. Other mineral products 
which have been produced in greater or lesser amounts are : antimony, 
asbestos, asphalt, bituminous rock, brick, chroraite, coal, dolomite, gems, 
gypsum, lime and limestone, magnesite, manganese, and mineral water. 

Barite. clay, copper, diatomaceous earth, feldspar, gold, iron, mont- 
morillonite, petroleum, strontium, and volcanic ash also occur here, 



192 DIVISION OP MINES AND MINING 

but the commercial value of tliese dejwsits is not as yet established 
A number of other mineral spec-its are represented in the county, but 
llieir occurrence is of mineraloy:ical interest only. 

Clay Resources. 

There have been a number of reported occurrences of high-grade 
clay in the county, but none of these have been of sufficient economic 
interest, in view of the comi)arative isolation of the county from indus- 
trial centers, and the lack of cheap transportation from the reported 
occurrences, to warrant serious investigation. 

The larger valleys of San Benito Kiver and its tributaries contain 
ample supplies of common clay suitable for the manufacture of heavy 
structural ware. The Paicines deposit, described herein, is typical ot 
these. There has been no commercial output of clays, as such, in the 
county, and the only clay material being utilized at the present time 
(19'2(i) is that mined by the Old ^Mission Portland Cement Company for 
the manufacture of cement at their plant at San Juan Bautista. 

Abbe Ranch. There is a deposit of clay containing considerable 
sandy material on the C. H. Abbe Ranch, 12 miles south of Paicines 
on the Idria road. This clay fuses at a rather low temj^erature. but 
does not crack or swell. It appears to be an impure montmorillonite. 
The bed stands i)ractically vertical and cuts across a ridge from top to 
bottom. 

A white kaolinized rock that slowly breaks down in water, forming a 
slightly plastic clay with a comparatively low fusing point, is exposed 
in a cut along the San Benito road about IS miles south of Tres Pinos. 
This variety of clay could probably be utilized in the ceramic indus- 
tries. It is undeveloped. 

The Alpine Quicksilver Mining Company in 1915 burned about 260,- 
000 brick in field kilns on lower Clear Creek near Hernandez for use 
in building their reduction furnace. The clay was dug locally. Some 
of these brick still remain along the road and appear to be of good 
quality. 

W. T. Maeder, 554 Sixty-sixth Street, Oakland, California, has sub- 
mitted a sample of siliceous clay, jiossibly a fireclay, from the Bitter- 
water section. Undeveloped. 

M. A. Martin, formerly of Ilollister. located some clay which burns 
white, or nearlv wliite. near tlie head of Willow Creek in T. 15 
S., R. 6 E. ■ 

Dr. J. M. O'Donnell of Ilollister owns a deposit along Bird Creek, 
three miles south of Ilollister. The bed is exposed for a considerable 
depth in several of the gulches, and a well was sunk 80 feet without 
reaching the underlying rock. The clay is light grey in color, very 
plastic and without grit. It burns to a cherry red and is said to be 
suitable for pottery use. 

Paicines Clay Deposit. In Sec. 36, T. 12 S., R. 6 E., M. D. M., 0.3 
mile south of Paicines on the San Benito road is an exposure of yellow 
plastic clay of ]n-obable Pliocene age. A road cut at this point exposes 
a bank 6 feet high, but the deposit is probably at least 20 feet thick, 



CLAY RESOURCES AND CERAMIC INDUSTRY 193 

and covers an area of many acres, with little or no ovei-burden. Similar 
deposits occur in various other localities in the San Benito Valley. 
See sample No. 118, page 341. 

H. y. Vndi rwood of Ilollister has submitted samples of plastic clay 
of fairly-high alumina content found at several points in the county. 

Bibl (On San Benito Count v clav resources) : State Min. Bur. 
Bull. 38, p. 226; Prel. Kept'. 7, p". 91; Kept. XXII, pp. 228-229. 

SAN BERNARDINO COUNTY. 
General Features. 

San Bernardino, with an area of 20,157 square miles, is by far the 
largest county in the state. It is bounded on the north by Inyo County, 
on the east by the states of Nevada and Arizona, on the south by 
Riverside County, and on the west by Los Angeles and Kern counties. 
The population IS 73,401 (1920 census). 

The topography of the county consists largely of mountains and 
desert, and is characteristic of the Great Basin, which has been 
described by many geologists. The famous Mojave Desert is almost 
wholly confined within the limits of the county, but extends southward 
into Riverside County. ^lost points in the county can be reached witli 
comparative ease by railroad or highway. 

The geology of the entire county has never been studied in detail, but 
many interesting reports have been made by various members of the 
r. S. Geological Survey, and others, on different areas in the county. 
A large i)art of the county is covered by Tertiary and Quaternary vol- 
canics, and Quaternary gravels, but many other formations are present, 
particularly in the numerous mountain ranges. Chief among these 
are i)re-Cambrian and Paleozoic metamorphics, and various Tertiary 
formations, principally ^Miocene. 

The mineral resources are varied, and the aggregate production 
places the county in fifth place (1926) among the counties of the state 
in the value of its mineral products. Cement is the most important 
product, and there are three plants in the county. Other mineral 
products are borates, calcium chloride, clay, copper, fuller's earth, gold, 
lead, lime, limestone, mineral water, petroleum, pota.sh, salt, silver, 
soda, miscellaneous stone, talc, and tungsten concentrates. Occur- 
rences of a.sbestos, barytes, gems, granite, gypsum, iron, manganese, 
marble, mineral paint, nitre, soapstone, strontium, vanadium, and zinc 
are known. 

Clay Resources. 

Deposits of high-grade clay occur at a number of localities in the 
county. Two or three of these have been developed. The most inter- 
esting deposits are those in the Hart :\Iountains, described below under 
H. F. Coors and Standard Sanitary Manufacturing Company. A 
plastic kaolin of exceptional quality has been developed on these prop- 
erties. It is likely that more intensive prospecting will disclo.se hitherto 
unknown deposits of a similar type. 

Common clays are sufficiently abundant in the vicinity of San Ber- 
nardino to serve all purposes, and the apparent lack of suitable deposits 

13 — 5+979 



194 



DIVISION OF MINES AND MINING 



elsewhere in the eoiiiity is of no importance, because of the fact that 
these areas can never be expected to snjjport a larj^e popiUation. 

Two ceramic materials of special intei-est occur in San IJernardino 
County, convenient to railroad trans|)ortatiou. These are ganister 
and talc schist. A large ganister deposit is beinu' Avorked bv the Atlas 
Fire Brick Company of Los Angeles in Sec. IM, T. 9 N., R. 3 W., four 
miles from Hicks Station on the Santa Fe railroad, betAveen Victorville 
and Barstow. It is the equivalent of Pennsylvania ganister in the 
manufacture of silica brick. The talc schist occurs in Sec. 29, T. 19 N., 
R. 4 E., 13 miles northeast of Newberry Station on the Santa Fe rail- 
road. It is being mined by John J. Kennedy of Daggett, and is in 
use as an ingredient of white tile bodies in a few Los Angeles plants. 

H. F. Coors Deposit. Owned by H. F. Coors, Inglewood. The i)rop- 
ertv consists of 7^ unpatented mineral claims in the old mining town of 
Hart. The claims cover parts of Sees. 13 and 24, T. 14 N., R. 17 E., 




Photo No. 58. H. F. Coors Kaolin Deposit, Hart, San Bernardino County. 

(Sample No. 57.) 



S. B. M. The clay is a white-burning ball clay, possessing the properties 
of a mixture of china clay and ball clay. It occurs as an alteration of 
an eruptive rock relatively high in alumina and low in alkalis and iron. 

At the time of visit, in June, 1925, the property was idle, but enough 
development work had been done in two different places, one of which is 
shown in photo No. 58, to demonstrate the presence of an extensive 
deposit of uniform material. The trench shown in the photo was 150 
feet long, 8 feet deep, and 15 feet wide. Ten to fifteen feet vertically 
below the bottom of the trench, a lOO-ft tunnel had been driven. At 
another point on the property, about 200 yards to the southeast, a 65-ft. 
tunnel, originally driven in the search for gold, had been enlarged at 
the face into a room 20 by 12 feet in section, by 8 feet high, exposing 
similar material to that present in the cut. 

Since 1926 Mr. Coors has been mining from the deposit to secure 
clay for his plant in Inglewood (see under Los Angeles County). 



CLAY RESOURCES AND CERAMIC INDTTSTRY 195 

Sample No. 57 Avas takon for tostiiij;, the results of whieli are on 
liajze 264. 

(}Ja<ldi)ig, McTiran <in<l Conrpnin/. Ofifice of Southern Division at 621 
S. Hope Street, Los Anproles. This eompany owns a dejiosit of bnff- 
hurnins: clay, 4.2 miles by road noi'tlieast of Bryman, a station on the 
Santa Fe railroad between Victorville and Barstow. The clay is mined 
from an open cut, which at the time of visit, in June, 1925, was 40 feet 
wide and 100 feet lon<>'. The bank was 40 feet hip'h at the face of the 
pit. Pi"oni 100 to 150 tons per year were beinp; mined and shipped to 
Los Anofeles for use in the manufacture of face brick. 

Sample No. 55 was taken for testin<r. The results are on paue 314. 

7?. H. HolJiman and D. Murphy have located 12 mineral claims cover- 
infr extensive outcrops of clay beds in Sec. 14, T. 12 N., R. 14 E., 
S. B. ]\r., on the western slope of the ]\fid Hills, which connect the 
Providence ^fountains on the southwest with the New York ]\[ountains 
to the northeast. By the existing road, the deposit is 13 miles southeast 
of Cima, but a road with easy down-grade could be built fi-om the 
deposit to the Los Angeles and Salt Lake Railroad line south of Tima. 
This road would be from six to seven miles in length. 

On the area covered hj the claims there are three distinct beds of 
white semi-plastic clay, each of which is from six to fifteen feet thick 
and can be traced intermittently for some 2000 feet on the strike. 

The clay shows the general characteristics of an impure kaolin, and 
is evidently derived from a highly feldsj^athic granite that is abundant 
in this locality. The (puility of the clay as exposed on the surface and 
in the shallow Avorkings is widely variable and it is likely that consider- 
able development work will be needed in order to prove the existence 
of sufficiently large bodies of material of uniform quality to warrant 
commercial ])roduction . 

Development: The deA^elopment work consists, in ]iart, of a shaft 
ten feet deep from the bottom of -which ten feet of drifting has been 
done. The clay bed at this point is steeply tilted and the attempt was 
made to cut it by a 12()-foot tunnel 25 feet below the outcrop, but so 
far as the work had progressed at the time of visit on June 18, 1925, 
the material encountered in the tunnel was inferior in quality to that 
exposed nearer to the surface. 

The other tAvo clay beds lie higher up on the mountain, and no 
development has been done. The upi)er beds lie nearly horizontal. 

The geology is somewhat complex in this area. There are a number 
of rhyolitic flow^s, as well as a few remnants of sedimentary formations, 
princii)ally sandstone and limestone. 

Sample No. 46 was taken for testing. The results are on page 349. 

MiUei Clay Deposit. An extensive, but undeveloped deposit of clay 
occurs near the southern boundarv of the Avest half of Sec. 31, T. 9 N., 
R. 3 W., S. B. M., OAvned by M. J. 'Millet and J. J. Kennedy of Daggett. 
The claA' is exposed on the surface one-third of a mile south of a ganister 
deposit that is OAA^ned by the Atlas Fire Brick Company of Los Angeles. 
Several shalloAv i)its and short tunnels liaA'e been excaA^ated, giving 
indications of a clay bed 10 to 20 feet thick and extending discontinu- 
ously for a distance of nearly one-half mile, Avith an east-west strike. 



196 



DIVISION OP MIXES AND MININO 



It is impossible to estimate from the present state of development the 
l)robable tonnage and uniformity of the occurrence. !Sami)le Xo. 53 
was taken for test, and the results ^iven on pa<;e 2S8 are sufficiently 
encouraging to Avarrant further investigation. The sample was taken 
from a shallow exposure made in a small cut, and it is not unlikely 




Photo No. 59. Pacific Kaolin Mine. Standard Sanitary Co. 
Upper worlvings. (Sample No. 45.) 

that it shows more contamination with surface debris than would be 
found at points further beneath the present surface. 

Standard Sanitary Companij. One-half mile south of the old gold- 
mining town of Hart, the Standard Sanitary Company owns a deposit 



CLAY RESOURCES AND CERAMIC INDUSTRY 



197 



of \vliite-burniii<i- hiill chiy that is bciim exploited by unclerground 
nietbods. 

Tbe clay is the residt of altoi-ation of a foldspathie ip'iieotis rock, the 
original nature of ■which was not determined. The enclosing and over- 
lying rocks are rhyolite. The total extent of the deposit is unknown, 
but the height is from 60 to 70 feet, the width at least 50 feet, and the 
length over 200 feet, as exposed on tlie sui'face and in the workings. 
The dimensions given probably represent but a small proportion of the 
total material available. 

Development and Mininc; : The development work consists of two 
sets of workings. The upper workings, now abandoned, lie up the 
slope of the hill some 80 feet vertically above the present tunnel level. 
The upper workings consist of an open cut extending into several 
underground chambers from which clay has been mined. See photo 
No. 59. 




Photo No. 60. Pacific Kaolin Miiio. Standard Sanitary Co. Trestle and bin on 
lower tunnel level. (Sample No. 4 4 taken from face of stope.) 

The lower tunnel was driven in order to provide better facilities for 
breaking and loading the clay, and to permit more systematic mining. 
At the time of visit on June 17, 1925, this tunnel had been driven 150 
feet in length and shortly after entering the hill, it had been gradually 
enlarged to a chamber which at the face was ;^0 x 30 feet in section. 

The clay requires liglit bla.sting but is sufficiently soft so that hand 
augers can be used for most of the drilling, with the aid of hand- 
hammer drilling in the harder portions. The broken material is hand- 
loaded into mine cars and hand-trammed to the loading bins outside 
of the portal of the tunnel. See ])hoto No. 60. A motor truck is used for 
hauling to Ivanpah, a distance of 15 miles over a rough road, but one 
that has a uniform down-grade in favor of the load. 

At the time of visit, four men were working, including the foreman 
and the truck driver. The i^roduetion varies from 15 to 20 tons per 
day. 



198 DIVISION OP MINES AND MINING 

This propertj' is worked for three or four months of the year. 
During the idle period the same crew is employed at the company's 
feldspar property' near Campo, San Diego Count}'. 

Samples No. 44 and 45 were taken for testing. The results are given 
on page 264. 

Bibl (Clay resources of San Bernardino County) : Cal. State 
Min. Bur. Bull. 38, pp. 226-227, 253-254; Prel. Kept. 7, pp. 
92-93 ; Kept. XV, pp. 860-862. The most important references 
on the geology of the county are : Darton, N. H., et al.. Guide 
Book of the Western U. S., Part C, U. S. G. S. Bull. 613 ; Ball, 
Sidney II., Geologic Reconnaissance of Southwestern Nevada 
and Eastern California, U. S. G. S. Bull. 308. 

SAN DIEGO COUNTY. 
General Features.* 

San Diego was discovered in September, 1542, by Juan Rodriguez 
Cabrillo. This discovery of the San Diego region by Cabrillo was fol- 
lowed by the establisliment of tlie first Franciscan ^Mission in California 
on June 16, 1769, by Padre Junipero Serra. The location of tliis 
mission at San Diego led to tlie early settlement of the Pacific coast 
and is of special prominence in the early history of California. 

The principal industries are agriculture, stock raising, dairying, and 
commercial fisheries. The mining industry is relatively undeveloped, 
although the mineral resources of the county are varied and extensive. 
Tlie rapid and continued growth of the city of San Diego and the manu- 
facturing industries on tlie Pacific coast have led to the development 
of deposits of structural and industrial materials throughout the 
county. 

San Diego is bouiuled on the east by Imperial County, north by 
River.side and Orange counties, west by the Pacific Ocean, and south by 
Mexico. Its area is 4221 square miles and its population 112,248 
(census of 1920). 

The countv and the citv of San Diego are served bv two railroads, 
the Santa Fe and the San Diego and Arizona. The Santa Fe railroad 
enters the county at San Onofre and follows the coast line to San Diego, 
connecting the lattter with the city of Los Angeles. From the main 
trunk line there is a branch line from Los Angeles Junction, known as 
the Fallbrook branch, that runs as far as Fallbrook ; another branch 
line runs from Oceanside to Escondido, giving railroad transportation 
to an important citrus belt. The San Diego and Arizona railroad runs 
along the border of ^Mexico and the county, connecting San Diego with 
Imperial Valley at El Centre. The Cuyamaca branch of this line runs 
from San Diego to Lakeside, affording transportation for El Cajon 
Valley and other interior points. From the port of San Diego regular 
steamer lines plv between San Diego, Los Angeles, San Francisco, 
Seattle. 

San Diego has a wonderful system of highways and good roads which 
give access to all parts of the county. Two main paved highways from 
Los Angeles to San Diego parallel the coast. The coast route follows 
the coast line, and the inland route is via Riverside, Fallbrook and 

• This and the subsequent paragraphs on geoloRv are abstracted from a recent 
report by W. Burling Tucker, State Mineralogist's Kept. XXI, pp. 325-327, 1925.. 



CLAY RESOURCES AND CERAMIC INDUSTRY 199 

Escondido to San Diego. Two paved liiglnvays eoniieet Imperial Valley 
with San Dieyo. Five scenic higliways, stretching out from San Diego 
like ribs of a huge fan with its northern tip at Oceanside and its south- 
ern tip at Campo, within one mile of the Mexican border, atford easy 
access by automobile to all parts of the San Diego Mountains. Each 
one of these intersects the road, forming the outer rim of the fan, which 
traverses practically the entire Incopah Range from northeast to south- 
west, a distance of more than 170 miles. The total mileage of all the 
fan-shaped routes is nearly 600 miles. 

The to])ographic features of the count}' consist of a series of parallel 
ranges of granite, witli a southeast trend, including the soutlieastern 
continuation of the San Jacinto Range of Riverside County. Among 
these granite ranges are valleys occupied by ])arallel belts of meta- 
morphic rock, chiefly slate and mica schist, witli some quartzite and 
lentils of limestone. These have a general northwest strike, Avith steep 
dips to the east, and extend from Mexico into Riverside and Orange 
counties. The Cuyamaca and Laguna Mountain ranges extend north- 
west and southeast, and are over 5000 feet high at many i)oints. Cuya- 
maca Peak has an elevation of 6515 feet, and Laguna Mountain an 
elevation of 6500 feet. These are intrusions of diorite and gabbro 
Avliich occur at intervals in the granite area. Southwesterly from this 
elevated belt the altitudes decline toward the coast. West of the granite 
area is a belt of volcanic felsite and tuff that extends northwest some 
40 miles from the Mexican line. The belt is only a few miles wide, for 
the most part being buried beneath mesa formations. It is exposed at 
many points, forming the peaks of Otay, San Miguel, and Black Moun- 
tains. The mesas of Tertiary deposits which occur on the west flank 
of the crystalline formations gently slope seaward, from an altitude of 
about 500 feet at its eastern margin to an elevation of about 300 feet 
near the coast line. From the main divide the surface slopes steeply 
eastward towai-d the Salton Basin. 

The principal valleys of the county are those occupied by the Santa 
Margarita, San Luis Rey, San Dieguito, San Diego, Sweetwater, Otay, 
and Tia Juana rivers. They are characterized by wide, flat, gently- 
sloping floors, bordered by steep slopes or bluffs several hundred feet 
high, and they contain streams that rise far back in the mountain area. 
All these streams flow to the ocean. El Cajon Valley, Santa Maria 
Valley, and Warner Valley are comparatively flat tracts, some of them 
surrounded by steep mountain walls, and cover many square miles, 
within the highland area, and form the broad valleys. 

Geology. 

The geolog;v' of San Diego County has been described in detail by W. 
A. Goodvear in the Eighth Annual Report of the State Mineralogist, 
pp. 516-628, for the year 1888 ; by Harold W. Fairbanks in the Eleventh 
Report, pp. 76-120, for the year 1892 ; by Dr. F. J. II. IMerrill in the 
Fourteenth Report of the State Mineralogist, pp. 637-6-45, for the vears 
1913 and 1914 ; in Water Supply Paper No. 446, U. S. Geological" Sur- 
vey, 'Geology and Ground Waters of the Western Part of San Diego 
County. ' 

The formations of San Diego County are granites and other igneous 
crystalline rocks, of several ages, metamorphic strata of great age. 



200 DIVISION OF MIXES AND MINING 

possibly Carboniferous or older, and sandstone, shales, conglomerates, 
sands, gravel, and clays of ^Mesozoic and Tertiary age. 

The granites upon Mhieh the metamorphic rocks rest, and by which 
they are intruded, are of .several types. These gi-anites are in turn 
intruded here and there by basic rocks of the diorite and gabbro types. 
The latter are cut at many points by pegmatite dikes, which also appear 
as intrusives in the schists and in the granites. Two area.s of these 
basic intrusives form substantial mountain ranges, one traversing the 
Cuyamaca Grant from north to south, and forming three peaks, of 
which the sonthermost, 6515 feet high, is known as ]\Iount Cuyamaca. 
Ten miles southea.st is a diorite ridge, known as Laguna ^Mountain, of 
which the summit attains an altitude of over 6500 feet. 

On the southwest flank of the granite area is a volcanic flow, a few 
miles wide, extending northwest some 40 miles from the Mexican 
boundary. This area is largely overlain by Tertiary formations. The 
])rincipal rocks exposed are felsite, tuffs, and volcanic conglomerates. 
The metamorphic formations are mica schi.sts. slates, quartzites. and 
limestone ; the mica schists are well exposed at Julian and on the west 
flank of the Laguna range of mountains. The Cretaceous strata 
exposed in this region are of the Chico series and appear in the bluffs 
on Point Loma and at La Jolla. as described by Harold W. Fairbanks 
in the Eleventh Report of the State ^Mineralogist, p. 95. 

The earlier Tertiary or Eocene depasits appear at the surface from 
Los Penasquitos Canyon northward to Buena Yista Creek; the later 
Tertiary deposits are exposed from Los Penasquitos Canyon southward 
to the ]\Iexican boundary, and from Buena Vista Creek northward to 
the north boundary of the county. The earlier Tertiary or Eocene 
beds are made up of white sandstone, underlain by alternating layers 
of shale, sandstone, and thin layers of clay and shale, limestone and 
sand.stone, and marl and calcareous material. 

The principal mineral products of San Diego County are miscel- 
laneous stone, feldspar, brick and hollow building tile, granite, and 
pottery clay. Other minerals that have been produced in recent years 
are mineral water, gems, gold, silver, fuller's earth (Otaylite'). lime, 
magnesium chloride, salt, and silica. Occurrences of bismuth, lithia, 
marble, nickel, soapstone, and tin are known. Potash has been pro- 
duced from kelp. 

Clay Resources. 

Important commercial deposits of fireclay and pottery clay, mainly 
of Eocene and Pleistocene age. occur in northern San Diego County, in 
the vicinity of Carlsbad and Cardiff. Some of the fireclays are similar 
to the famous Gros-Almerode clays of Germany. On the top of El 
Cajon ]\Iountain. in the southern part of the county, is an interesting 
deposit of residual kaolin. Avhich was worked for a short time, but has 
little commercial value on account of its inaccessibility. It serves as a 
valuable guide to further prospecting in the region. 

Red-burning .shales suitable for the manufacture of common brick, 
paving brick, and hollow tile are reasonably abundant in the vicinity of 
San Diego, but softer clays that can be used without grinding are not 
plentiful in locations close to the center of consumption (principally 
the city of San Diego). Deposits of Miocene Tertiary clays on the 



(LAY KESOl'HCKS AND CEKAMK' INDUSTRY 201 

eastern marjrin of the county were noted in an earlier report/ Tliese 
are as yet commercially inaccessible, and but little is known of their 
properties. 

The feldspar and ({uartz deposits of San Diciro County are of par- 
ticular interest to the clay-workin<; industry. The greater part of the 
feldspar used in California is produced at Camjio. 

Cdlifoniia Clay Produrts Companji and Mission China Compayv/. 
Victor Kremer, president. Offices, 315 Western Mutual Life Building, 
Los Angeh^s. The.se eom])anies own a fireclay property in Sec. 4, T. 
13 S., R. 3 W., S. B. M., 8 miles by road in a northeasterly direction 
from C'arditf. and two miles northeast of the property of Gladding, 
McBean and Company ((/.v.). 

The holdiiigs of the California Clay Products Company consi.st of 
the Pearl and the Dorothy Ann placer claims, comprising 20 acres each ; 
and the ]\Ii.ssion China Company owns tAvo adjoining claims known as 
the Robert Charles and the Thomas Hewitt, also 20 acres each. All 
these claims are i)atented. 

Tiie clay is a white, .semi-pla.stic fiireclay. It does not dcvelo]) suffi- 
cient plasticity to be used alone, and is of value principally for its 
refractoriness. It is used in Los Angeles by the California Clay 
Products Comi)any, as an ingredient in the manufacture of saggers, 
and also in San Diego by the Vitrified Products Corporation. These 
companies are controlled by the Victor Kremer Enterprises, Victor 
Kremer, president. 

Devkloi'MENT AND ]\IiNiNO : A number of test pits and trenches have 
been dug, ex])osing clay over a considerable area. ^Mining is being 
done on the Pearl claim, where a loading bin has been built and a small 
open cut, 30 by 40 feet in area, has been excavated. The ex])osed baidc 
of clay is 10 to 12 feet high. One carload per week is being mined and 
trucked to Cardiff. 

Sample Xo. 36 was taken for testing. See page 'Ml. 

Bibl: State Mineralogist's Report XXI, p. 355. 

El Cajon Kaolin Deposit. The deposit is located on Cajon ^Mountain, 
at an elevation of 2500 to 2700 feet, 41 miles in a direction X. 55 E. 
from Lakeside. It is now ow^ned by the American Pottery Company ( ?) 
of Los Angeles. The holdings comprise two claims in T. 14 S., R. 2 E., 
S. B. ]\I., on or near Sec. 29, approximately one mile west of El Cajon 
Peak, but practically on top of the range. 

The kaolin was formed by alteration in situ of an ala.skite or similar 
])egmatitic derivative, containing but small quantities of ferro-manga- 
nesian minerals. The extent of alteration varies widely within com- 
paratively short distances, so that the resultant material ranges from 
slightly-plastic kaolin containing an excess of free quartz and unde- 
composed feldspar, to extremely plastic, fine-grained, thoroughly- 
hydrated kaolin. Exposures of such material have been made at 
various points on the mountain, indicating that they occur in a zone 
that has a general northeast strike. 

The deposit has been developed by a number of t.iinnels, shafts, and 
open cuts, the principal tunnel having been driven m a northwesterly 

' State Mineralogist's Report XIV, p. 685. 



202 DIVISION OF MINES AND MINING 

direction for a distance of 75 feet, to a point 50 feet below the surface. 
This tunnel is connected by means of a raise to a small open pit, or 
glory hole. The material exposed by these workings shows all of the 
variations indicated above, witli six feet of thoroughly altered, plastic 
kaolin near the face. During 1914 and 1916, some kaolin from these 
workings was sliipped to the faience tile plant of the former California 
China Clay Products Company at National City. The total quantity 
shipped probably did not exceed 400 tons, to judge from the extent of 
the workings. The material was packed b}^ mules over a rough and 
steep trail to a point on the San Diego River, then hauled by wagon to 
Lakeside, at a cost said to have been $7.50 per ton, exclusive of mining. 
Due to its inaccessibility, there has been no work on the deposit since 
1916, excepting annual assessment work. 

Two samples, Nos. 37 and 38, were taken and tested, the results of 
which are given on page 259. 

Bibl: State Mineralogist's Report XXI, p. 354. 

Gladding, McBean and Company. Office of Southern Division at 621 
S. Hope Street, Los Angeles. This company owns a deposit of clay, 
of Eocene and Pleistocene age, on the Las Encinitas Ranch in the town- 
site of Olivenhain. Tlie property includes a portion of Lot 18, and 
adjoins the property of the Vitrified Products Corporation {q. v. post) 
on the west. 

At the time of visit, on June 9, 1925, the clay was being mined from an 
o])en cut, tlie floor of which was about 75 feet square. The l)ank was 30 
feet high at the face of the pit. ]\Iining was by hand, loading into small 
mine cars, whicli were trammed over a trestle to a bin, from which auto 
trucks were loaded. Three or four cars per week were being mined 
(luring ])art of tlie year, the annual production being 5000 to 7000 tons, 
which was used in the company's plants in Los Angeles. The clay is 
a red-burning material, with good plasticity, and is useful in face brick 
and sewer pipe mixes. Sample No. 35 was taken. The test results are 
on page 322. 

Since the property was visited, it is understood that considerable 
drilling and other development work has been done, with the result 
that excellent deposits of fireclay have been found, in addition to the 
red-burning clay already known. The fireclays are said to closely 
resemble the Gros-Almerode clays of Germany. 

H. T. Morris of Escondido owns a deposit of clay one mile south 
of Richland Station on the Escondido Branch of the Santa Fe Rail- 
road. 

The clay occurs in a low hill and is covered by black adobe .soil. 
The deposit has not been developed and good exposures of the fresh 
clay are lacking. The deposit is apparently at least 15 feet in thick- 
ness, and underlies .several acres of land. The attempt was made some 
time ago to make common red brick from this clay, but it Avas unsuc- 
cessful largely because of im])roper mixing, tempering, and firing of 
the brick. Some specimens of earthernware made from this clay can 
be seen in the Chamber of Commerce exhibit at Escondido. 

Sample No. 41 was taken for testing. See page 348. 

Bibl: State Mineralogist's Report XXI, p. 355. 



CLAY RESOURCES AND CERAMIC INDUSTRY 203 

National Brick Company. William ]\Iulford, president ; Edward 
Harrie, Jr., secretary. Offices and i)lant are located at Twenty-fourth 
JStreet and National Boidevard. National City. The holdings of the 
company comprise 13 acres, under lease from S. Christian, of National 
City. The company is manufacturing common red brick from adobe 
clay. The clay is hauled by scrapers to a liopper, from which it passes 
to a set of rolls, where the clods are broken up. It is then conveyed 
over a belt conveyor to a pug-mill, from which it passes to a brick press. 

The brick are dried in sheds. The dried brick are fired in ojien oil- 
fired kilns. The plant is driven by a 50-h.p. electric motor, and has a 
capacity of 36,000 brick per day. Fifteen men are employed. 

Old Mission Tile Compayv/. W. C. Mitchell, president; J. F. Keenan, 
secretary; P. 0. McCarthy, treasurer. Office and plant in North San 
Diego. This company was organized in 1927 with a capitalization of 
$50,000, to manufacture hand-made roofing and promenade tile.^ 
Further details are lacking. 

Pacific Clay Products Company. Wm. Lacy, president ; Robert 
Linton, vice president and general manager. Offices, 1151 South 
BroadAvay Street, Los Angeles. Three miles east by road from Farr 
Siding, which is on the Santa Fe Railroad one mile south of Carlsbad, 
is one of the clay properties owned and operated by the Pacific Clay 
Products Company of Los Angeles. The property was formerly a 
part of the Kelley Ranch, and comprises 25 acres. 

The clay beds are exposed on a low rounded hill. The upper 10 
to 15 feet consists mainly of a white plastic vitrifying clay which is 
used in a mix for the manufacture of face brick and other products. 
This clay is slightly iron-stained, and is mixed with a small quantity 
of bluish plastic clay. 

Underlying the bed of white clay is a bed of mixed yellow and blue 
clay of undetermined thickness. This clay is also plastic and will doubt- 
less be extensively utilized as development of the property advances. 

Development and IMining : The clay has been prospected by means 
of a number of test pits on the property. Mining was formerly done 
with horse scrapers and plows and with a wheel scraper drawn by a 
tractor but more recently a "Bear Cat" shovel has been installed. See 
photo No. 61. A bench has been established for mining the upper bed 
of white clay separately from the yellow clay. The exposed bank of 
white clay is 275 feet long. A motor truck is used to haul the clay 
to Farr Siding. The production is 20,000 tons per year. 

Sample No. 39 of the white eluy, and sample No. 40 of the yellow 
clay were taken for testing. See pages 296 and 322. 

Other remnants of this same clay bed occur in various places on the 
Kelley ranch. Some test pits have been dug, but no deposit as satis- 
factory in quality or extent as that owned by the Pacific Clay Products 
Company has been disclosed. 

Bibl: State Mineralogist's Report XXI, p. 356. 

San Diego Tile and Brick Company. Wm. Roffe, president and 
manager. Office in San Diego. This companj^ controls 100 acres of 
land in Rose Canyon. The clay pit and brick yard are on the west side 

'Clay-Worker, August, 1927, p. 123. 



204 DIVISION OF MINES AND MINING 

of the canyon, 3.2 miles by road north from Balboa Avenue, Coast 
highwav. The material used is a Tertiarv shale, which is for the most 
part thin-bedded, moderately hard, and generalh' yellowish or yellowish 
g;ray in color. The same formation persists on the west side of the 
canyon for several miles. 

The clay is scraped into chutes alongside of the Rose Canyon Road, 
at a point 50 feet vertically above the yard. The clay bank at present 
exposed is about 75 feet high at its highest point, and 300 feet long. 
Practically no overburden is present. Common red brick and hollow 
building tile are made by the stiff mud process. Drying is done partly 
in the open air and partly under shed. The dried brick are fired in 
open oil-fired kilns. The plant is oi)erated as required to supply the 
local demand. 

Sample No. 30 was taken for testing. See page 339. 







i^V 



^':-A--' ' -- -■^.r "-- ' --* • 



'-^ - ■ 't^,'';::^ •^'^^W 



Photo No. 61. "Bear Cat" shovel at Kelly No. 1 mine, Pacific Clay Products Co., 

p-arr siding, San Diego County. (Samples No. 39 and 40.) (Photo by 
courtesy of the company.) 

Union Brick Company. J. W. Rice, secretary. Offices, 3565 Third 
Street, San Diego. The plant is 1.1 miles north of Balboa Avenue, 
Coast Highway, on El Camino Real through Rose Canyon. It is about 
two miles south of the yard of the San Diego Brick and Tile Company. 
The shipping point is Ladrillo Station on the Santa Fe Railroad. 

The clay, while apparently belonging to the same stratigraphic series 
as that of the San Diego Tile & Brick Company's deposit, is somewhat 
different in character, and consists mainly of a loose conglomerate 
composed of pebbles and boulders of all sizes up to two feet in diameter, 
intermingled with loose yellowish clay. Underlying this material is a 
bed of plastic clay shale, blue-gray in color. 

The clay is mined with Fordson tractors and scrapers Avhich dump 
the material into a chute leading to the brick yard located in the 
bottom of the canyon. Common red brick only is made at this point 
which is equipped with dry pan and two electric-driven presses. Oil- 



CLAY RESOURCES AND CERAi^flC INDUSTRY 



20;') 



firod oi)eii Hold kilns aro used. It is said tliat the clay lias vcrv little 
shrinkaji-p durinji: tho briek-inakino: process. 

Sample No. -"{l was taken I'oi- testinj;. See \)i\\xo 'MO. 

Vitrified Producis ('orporafion. Victoi- Kroiuoi", i)i-esident ; George 
Kumiuer, jreneral manaj-er; John F. Koonan, supei'intendent. Sales 
office, 522-24 Spreckels lUiilding, San Diego; general offices and plant 
in North San Diego. This jilant started operations in November, 1928, 
to make semivitiv^ons hollow tile, building tile, and brick. The com- 
pany owns two clay deposits, one at Linda Yista, the other near Carditf. 

Cardiff Deposit: This is a dei)osit of fireclay on the Las Encinitas 
Ranch in the townsite of Olivenhain. The holdings consist of a portion 
of lot 18 in Rancho Las Encinitas, and comprises 16.6 acres. The 
property formerly belonged to the Wiro famil}', and is known to local 



r'-'m^ 




4^ 




Urn, .-r; 




,^;--?^7*.^>ri^», 




I'HuTo No. 62. W'iro Mine. Fireclay deposit east of Cardiff. San Diego County, 
owned by the Vitrified Products Co. of San Diego. (Sample No. 34.) 

inhabitants as the Wiro Mines. It is 5.7 miles by road from Cardiff in 
an ea.sterly direction. 

The fireclay has been exposed by two small open cuts, each of which 
is abont 50 feet square, Avith a bank of 15 to 20 feet in height. The 
bed of fireclay is from 10 to 12 feet thick, and is overlain by a thin 
layer of soil and yellow, sandy clay. The beds are nearly horizontal. 
Sample No. 33 was taken from the north pit, and sample No. 34 is from 
the south pit, and the test results are on page 2S7. See photo No. 62. 

Underlying the fireclay is a bed of soft, loosely consolidated sand- 
stone containing clay as filling material. The fire clay is moderately 
hard and varies in color from a buff to blue-gray and light purple. 

At the time of visit (June, 1925), one to two cars per week were being 
rained and shipped from a siding one mile south of Cardiff. 

Linda Vista Deposit : This deposit is located on the south side of the 
Santa Ee Railroad at Mile 25], about two miles north of Linda Vista 
Station, in Sec. 9, T. 15 S., R. 3 W., S. B. M. 



206 DIVISION OP MINES AND MINING 

The holdintrs include the Ni and the NEJ of the SW] of the section, 
a total oi' 'MW aci'es. most of wliieii is appai-ently underlain by the 
clay beds. 

At the time of visit on June !), l!)2r), Ihe deposit had been opened by 
an electric shovel along- a face 300 feet long and 50 feet high, adjacent 
to and adjoining the railroad tracks. The material is a clay shale, 
light yellow in color, and the individual strata are from a fraction of 
an inch to one or two feet in thickness. Two or three beds of siliceous 
sandstone about one foot thick are interbedded with the clay shale. 
These are sorted from the clay whenever possible. In places the clay is 
more santly than in others, but is seldom too sandy foi' satisfactoiy use. 
The overburden is thin, varying from 6 inches to 3 feet in thickness. 
The same formation is quite extensive in this locality and can be traced 
for at least a mile along the Santa Fe tracks toward Linda Vista. The 
total thickness of the clay beds is probably not less than 100 feet. 

At the time of visit about 200 tons per week were being shipped to 
the San Diego plant. When the plant is operating at full capacity, 
300 tons per w^eek are shi]>ped. 

8am])le No. 32 was taken for testing. See page 322. 

San Diego Plant: At the plant in North San Diego hollow tile and 
building tile are made by mixing 25% of the Cardiff tireclay with 75% 
of the Linda Vista clay. The material is crushed to ^ inch and is fed 
from the crusher bin into a trough mixer, where it is tempered with 
water. The tempered clay passes through an auger machine and the 
tile are cut with an automatic wire cutter. The green tile are then 
hand-loaded on triple-deck trucks and trammed to the drying shed. 

When not working at full capacity, the drying is completed in three 
or four da3^s, but when crowded to capacit}- only one day is allowed for 
this part of the process. The drying is finished in oil-fired drying 
ovens where the heat is controlled according to the amount of moisture 
remaining in the tile. At times the dryer temperature is so high as to 
scorch the wooden pla.tforms of the trucks. 

The common brick are fired in open field kilns, using oil as fuel. 
The other shapes are fired in oil-burning round down-draft kilns. The 
firing temperature is from 2000° to 2100° F. for 4| to 5 days. An 
equal period is allowed for cooling. The firing range of the clays in 
use is 200° F. The brick and tile are remarkably uniform in color, 
which is a pink bordering on red. There is very little difficulty with 
lost ware and all of the products are strong and free from cracks. The 
drying shrinkage amounts to 1 in 11-J, and there is no cracking during 
the drying of the tile which are placed on the side rather than on end. 
The firing shrinkage is exceptionally low. 

The capacity of the plant is 50,000 brick and 50,000 hollow tile per 
day. 

Bibl: State Mineralogist's Reports XIV, pp. 685-688; XX, p. 369; 
XXI, pp. 354-358. Bull. 38, pp. 227, 254. 

SAN FRANCISCO COUNTY. 

The area of San Francisco County is 43 square miles, and tlie popu- 
lation is 506,676 (1920 census). The only mineral production in the 
county is crushed rock, sand and gravel. A number of brick yards at 



CLAY RESOURCES AND CERAMIC INDUSTRY 207 

oiu' lime ()|)t'i-a1('(l in the county, hut hiiul is uow more valuable for 
otluT i)uri)oses. 

The only ceramic plants in the county ai-e an art ^vare pottery at 
2928 Baker Street, San Fraiu'iseo, owned and oi)erated hy JaJanivich 
and Olsen, and a dental ])oreelain lahoratoi-y at 8:)() Market Street, 
known as Tara's Porcelain Lahoi'ofory. Jalanivich and Olsen are 
makinp: an attractive line of glazed pottery, usinf; a buff -burning body 
and lead glazes. Their output is all liand-niolded on a potter's wheel. 
It is tired in a round kiln, approximately 3-ft. inside diameter, of tlieir 
own design and built by the gas company, city gas being used for fuel. 
The clav, from California sources, is fired up to 2000° and the glaze 
to KiOO'^-lTOO". 

SAN JOAQUIN COUNTY. 
General Features.' 

The county lies mainly in the great valley of the same name in the 
central portion of the state. It is bounded on the north by Sacramento 
County, on the east by Amador, Calaveras, and Stanislaus. The latter 
county extends around and adjoins it on the south also. Contra Costa 
and Alameda counties lie west of it. 

Stockton, the county seat and largest city, has water transportation 
facilities, as well as rail. The area of the county is 1448 square miles, 
aiul its population is 79,905 (1920 census). By far the greatest part 
of its area is made up oF farm lands ; the so-called 'delta' region adjacent 
to Stockton being noted for its rich peat soil and heavy crops. 

The luost extensive geological formation exposed consists of uncon- 
solidated sands, gravels and clays of Quaternar\' age, which compose 
the nearly-level valley floor. Tlie western edge of this formation fol- 
lows closely the Southern Pacific railroad line down the west side of 
the valley from Bethany to Vernalis. The corner of the county, south- 
west of the railroad, is composed of marine sandstone, and diatomaceous 
and clay shales of Tertiary and Cretaceous ages in the northern part. 
Its south half is rugged and broken, as the Franciscan rocks, typical of 
the Coast Range, including slates, cherts, linu'stones and sandstones, 
witli much scliist and ser})entine, are exclusively in evidence. 

Unconsolidated sands, gravels and clays extend practically to the 
county line on the eastern side of the valley, the only other rocks 
exposed being two small areas of extrusive volcanic rocks, just east 
and north of Bellota. 

Comparatively few minei-al substances are found in San Joaquin 
County, and of these the most im])ortant are nonmetallic structural 
and industrial materials and natural gas. Gold, silver and platinum 
have been obtained by dredging in ]Mokelumne River. Clay and clay 
products accounted for more than half the total mineral production of 
the county in 1923. 

Clay Resources. 

Common clays suitable for the manufacture of brick are abundant 
in the county, and two brick yards are in operation. High-grade clays 
were at one time produced near the San Joaquin and Alameda county 
line, in the vicinity of Tesla and Carnegie, and were utilized at the 

* Laizure, C. McK., State Mineralogist's Rept. XXI, p. 1S4. 



208 DIVISION' OF MIXES AXn MINIXO 

l)]aiit of the Carnegie Brick and Pottery Company, which has been 
(lisnianthMl for many years. See under Alameda County for further 
(h'tails. 

One of the important fire brick plants of tlie state, that of the Stock- 
ton Fire Brick Company, is operating in Stockton. The i)lant is 
strategically situated with res])ect to the clay mines of Amador and 
Placer counties, and is within the range of chea}) transportation to tlie 
marketing centers. 

San Joaquin Brick Co. I. P. Stine, secretary-manager; Ernest 
Rossi, jjlant superintendent. Home office, 33 South El Dorado Street, 
Stockton. The property is located on a 60-acre tract on Roberts 
Island, six miles by road southwest from Stockton. Common red brick 
is the sole product. The clav is an extremely sandy bottom-land loam. 
The water level lies within six feet of the surface, so that economical 
mining has always been a serious problem. A horse-scraper is used 
above the water level, dumping through trap doors into horse-drawn 
cars operating on a light industrial track. A gasoline locomotive was 
])urchased and tried in place of horses for haulage, but the track was 
not of sufficient weight to obtain satisfactory results. 

Below the water level, the clay is excavated with a ^Marion steam 
shovel mounted on a barge. The clay is dumped along the bank, and 
allowed to dry in the air before it is reclaimed by the horse scraper. 

The soft-mud process is used for shaping the brick. The clay is 
given a double pugging before passing to a 6-mold press. A continu- 
ous rope conveyor takes the brick from the press to the drying sheds. 
The sandiness of the clay is indicated by the fact that the drying ])eriod 
in warm weather is only three days, with a maximum of five days in 
cooler Aveather. 

A Hoffman continuous kiln burning coal screenings is used for firing. 
The kiln is 175 feet long, with 12-ft. by 12-ft. chambers. The firing 
cycle is 14 days, and the capacity is 24,000 brick per day. The 
machinery is o])erated by electric power. The total installed ca]iacity 
of the motors is 100 horsepower. Forty men are employed. 

Bibl: State Mineralogist's Report XXI, p. 188. 

Stockton Brirk and Tile Co. Ralph Wilcox, president ; Paul Weston, 
secretary; G. Birtolini, plant superintendent. Home office, 245 North 
El Dorado Street, Stockton. The plant is on McKinley Avenue near 
the southern boundary of the city of Stockton, about one-half mile west 
of the Municipal Baths. A Southern Pacific spur track runs to the 
l)lant. The plant was built in 1921. Common brick and some hollow 
building tile are manufactured, using surface clay from the property. 

The claj^ is a bottom-land deposit of yellowish sandy loam and is 
mined to a depth of 15 feet below the surface by horse-drawn scrapers. 
The clay is found at greater depths, but is below the water level. The 
scrapers deliver the clay to a dry pan, from which the crushed product 
is elevated by a bucket elevator to a pug-mill and auger machine. The 
brick are taken from the wire-cutter belt by hand and loaded on trucks 
wliich are trammed by hand to oil-fired tunnel driers. 

Firing is done in a Hoffman continuous kiln. The capacity of the 
kiln is 450,000 brick, and 25,000 brick are set and drawn each day. 
Coal screenings from Utah coal are used as fuel. The coal lioles are 



CLAY RESOURCES AND CERAMIC INDUSTRY 209 

Spaced three feet apart. One man on each 8-hr. sliift attends to the 
firing. The fires must be carefully controlled, as the kiln is too short 
for successful iirin<;' if irregular Hud nations in temperature are i)er- 
mitted. Natural stack draft is used. 

In order to keep the plant in continuous operation during the year, 
it is customary to shape 40,000 brick, or the ecpiivalent volume of brick 
and hollow tile, per day, during the summer and fall. Half of this 
output of green ware is stored for firing during the winter months, so 
that it is not necessary to operate the pit or the auger machine during 
the wet season. 

The plant emploj^s 25 men during the summer and about 15 men 
during the winter. The annual output is over 3,000,000 brick, or an 
equivalent volume of brick and hollow tile. The hollow tile production 
is never a large proportion of the total. All machinery is operated by 
electric power. 

Bibl: State Mineralogist's Report XXI, p. 188. 

Stockton Fire Brick Co. John T. Roberts, i)resident ; Percy T. Cleg- 
horn, secretary ; E. H. Horner, plant superintendent. JMain office, 12 
Russ Building, San Francisco. Plant address, P. 0. Box 314, Stockton. 

The company's plant is just west of the Southern Pacific railroad at 
the foot of S. California Street, Stockton. See photos No. 6:} and 64. 
The outi)ut includes several different grades of fireclay brick and 
special shapes, high-temperature fireclay cement, and diatomaceous 
insulating brick. The companj^ owns or leases deposits of most of 
the raw materials in use at the plant, the most important of these being 
Edwin clay (No. 120, p. 272), from Jones Butte near lone; lone sand 
(No. 140, p. 280), from the pit of the lone Fire Brick Co., and Lincoln 
fireclay (sample No. 280, p. 305), from the newly developed pit of a 
subsidiai-y company, the Clay Corporation of California. Quartz for 
grogging some of the grades of fire brick is purchased from various 
California sources, mainly in Placer County, and diatomaceous shale 
for the manufacture of insulating brick and special shapes is purchased 
from producers in Santa Barbara County. 

The princii)al grades of fire brick are as follows: 'Gasco XX," quartz 
grogged, auger-made, single pressed ; ' Stockton, ' quartz grogged, auger- 
made, repressed ; ' Gasco R, ' quartz grogged, auger-made, repressed ; and 
'Carnegie,' which is grogged with calcined fireclay, hand-made in 
sanded molds, and repressed. The 'Carnegie' brick is the best grade 
of standard brick being produced at present for resisting high tem- 
peratures under adverse load and spalling influences. Among the 
specialties regularly produced are a high-grade checker-brick which is 
made from a mixture grogged with calcined clay and shaped on an 
end-cut auger machine, and runner-brick, made from a similar mixture, 
formed on an auger-machine, and then passed to a specially designed 
machine for making the joints and cutting the side-holes. 

The mixtures are prepared by dry-pan grinding, followed by pug- 
mill tempering for the material that is to be hand-molded. 

All of the shapes except runner brick are dried in waste-heat tunnel 
driers. The runner brick, which require especially uniform drying 
on all sides during the shrinkage i)eriod, are dried in a Carrier ejector 
humidity drier, which is operated on a 13 to 15 hr. schedule, beginning 

14—54979 



210 



DIVISION OF MINES AND MINING 



'tm 


V 


1 '■ 




1 t??IB 


j 1 


4 


1 


p 










4:- 


-' 


ji 




*, 


— ^ m^ 




^h 




if: 






iBsjS'' 




1 




Sh 




■ 

M 1 


1 



c 
o 
y 



V 



3 
O 

rj 



3 
O 



c 
m 

c 

o 

-t-t 
X 

o 

o 






O 
U 

a 

"u 
H 



fa 

c 
o 

a 

o 



J3 



CO 

to 

d 

O 

o 
K 



CLAY RESOURCES AND CERAMIC INDUSTRY 



211 



with a tliree-hour [xM-iod at Ho"" F. and 40'/ humidity, and finished 
at 240° to 250 F. with steadily declinin<>- humidity. The brick are 
set on tlie drier ears in a direction parallel to the dii-eetion of the air 
current in the drier, so that the air passes tlirou^ih and around the 
brick simultaneously, thus drying the inside and outside of the brick 
at the same rate. 

The manufacture of diatoniaeeous insulating' brick, known by the 
ti-ade name 'Diatex,' is becoming an increasingly iini)ortant part of the 
0|)erations of the phmt. Standard 9-in. brick and many special shapes 
are made. They are liaud molded from diatomaceous shale containing 
sufficient clay for boiidiiiu. Slow and cai-eful uniform drying is neces- 




Photo No. 64. Clay bins and dry pans In plant of the Stockton Fire Brick 
Company. (Photo by courtesy of the company.) 

sary to avoid loss by warping or cracking. In connection with the 
development of this i)roduct a conductometer, the i^rinciple of which 
has been described by K. I). Pike,^ was constructed in the laboratory, 
for the purpose of comparing the heat conductivities of the various 
experimental mixtures. 

The fireclay ])roducts are fired in 12 oil-fired round down-draft 
kilns, which are of various sizes from 12-ft. to :32-ft. in diameter, with 
capacities ranging from 80 to 400 tons each. The usual firing cycle 
is seven to eight days firing, to a temperature of 1370° C, correspond- 
ing to cone 11 down, followed by a cooling period of equal length. 

• Pike, R. D., Need for more refractory heat insulators : Pro])osed conduetometers 
for measuring thermal conductivity: Jour. Amer. Cer. Soc, 5, 554, August, 1922. 



212 DIVISION OF MINES AND MINING 

The insulating brick are fired in fonr 12-ft. hy 23--ft rectangular 
kilns. 

liJase-metal thcrinofouijles with automatic recorders are installed in 
all kilns for the accurate control of the firing cycle. 

The plant is noteworthy for the high degree of technical control to 
which all operations are subjected, and for the continual improvements 
that are being made in the processes of manufacture and in the (juality 
of the finished product, through the cooperation of an efficient technical 
staff and a progressive management. 

An average of 110 men are employed. 

Bibl (Clay resources of San Joacjuin Count v) : State Min. Bur. 
Bull. 38, pp. 227-228; Prel. Kept. 7, pp. 91^95; Kept. XIV, pp. 
607-610, and XXI, pp. 188-190. 

SAN LUIS OBISPO COUNTY. 
General Features.^ 

San Luis Obispo County borders on the Pacific Ocean and occupies 
a position midway between San Francisco and Los Angeles. It is 
bounded on the north by Monterey County, on the east by Kern and 
on the south by Santa Barbara. It contains 3334 square miles and 
has a population of 21,893 (1920 census). The coast line of the South- 
ern Pacific railroad passes through the county from north to south. 
The railroad follows Salinas River Valley through Paso Robles to a 
point near Santa Margarita, thence it crosses the Santa Lucia Range 
via Cuesta Pass, reaching San Luis Obispo at the foot of the grade, 
and the ocean near Pismo. It continues south along the ocean shore, 
giving through transportation. The Pacific Coast railroad (narrow 
gauge) connects Port San Luis with San Luis Obispo and continues to 
Santa Maria and other points in Santa Barbara County. The paved 
coast highway closeh- parallels the Southern Pacific railroad through 
the county. 

From Santa Margarita fair dirt roads extend to the eastern part of 
the county, but McKittrick, in Kern County, is a nearer railroad point 
to this section. Steamer service is available at Port San Luis. This 
harbor is the terminus of pipe lines from the San Joaquin Valley oil 
fields and is an important loading point for oil tankers. 

The Coast Range mountain system traverses the county from north- 
west to southeast. Within the county this mountain block consists of 
three main ranges, the Santa Lucia Mountains, the San Luis Range, 
and the San Jose Range. 

The geology of that portion of the county from the southern boundary 
to latitude 35° 30' N. and from the coast "to longitude 120° 30' W. has 
been described and mapped in detail by H. W. Fairbanks.- A discus- 
sion of the geology of the countv with relation to petroleum resources 
will be found in Bulletins Xo.' 69 and Xo. 89 of the State Mining 
Bureau. A folio of geologic maps accompanies Bulletin Xo. 69. 

As indicated on the Bureau's geological map of the state, the Santa 
Lucia Range from San Luis Obispo northwestward to the northern 
boundary line is made up of Franciscan rocks, including slates, cherts, 

' From Laizure, C. McK., San Luis Obispo County : State Mineralog-ist's Rept. 
XXI. pp. 499-501, 1925. 

= Fairbanks, H. "W^, San Luis Folio, No. 101 : U. S. Geological Survey. 



CLAY RESOURCES AND CERAMIC INDUSTRY 211] 

limestones, aii,d sandstones, witli nuicli serpentine and many dikes and 
intrusions of deeji-seatod iji'iieous roeks. On the tlanks of tlie range are 
narrow belts of Cretaeeous sandstone and shales. Southeast of San 
Luis Obispo the formations are mainly Tertiary marine sandstones 
and diatomaeeous shales. Unconsolidated sands, jijravels, and clays 
extend from Pismo to Santa IMaria River and well up tlie valley of the 
Santa Maria. East of Santa Margarita there is a large area in which 
granite predominates. The balance of the county lying east and north 
of the Santa Lucia Range consists almost entirely of sedimentary rocks 
of Tertiary age, shales, sandstones, tuffs, and gravels with an area of 
Quaternary sediments comprising Cai-rizo Plain. 

Among the mineral resources of the county, both developed and 
undeveloped, are asphalt, bituminous rock, brick, chroniite, coal, copper, 
diatomite, gypsum, iron, limestone, marble, mineral water, onyx, 
l)etroleum, quicksilver, soda, aiul miscellaneous. Miscellaneous stone, 
l)etroleum, brick, and mineral water are the principal commercial 
mineral products at present. 

Clay Resources. 

There are no known deposits of high-grade clays in this county, but 
red-burning clays suitable for making brick occur in the vallej^ silts of 
recent origin at various places. Since the population of the county is 
small, the demand for claj' i^roducts is limited, and a single common- 
brick plant at San Luis Obispo sup])lies the market of the county as 
well as of a few nearby towns in Santa Barbara and Monterey counties. 
The territory to the south is supplied by brick yards in Santa Barbara, 
while plants in San Jose furnish brick for the communities in Monterey 
and San Benito counties. 

San Luis Brick Works. Owned and operated by Faulstick Bros., 
San Luis Obispo. This plant, formerly known as the San Luis Brick 
C^ompau}', is located one mile south of town, near the lines of the 
Soutliern Pacific and Pacific Coast railroads. The clay is a yellowish 
loam, with little or no overburden. The proportion of sand is sufficient 
to prevent excessive shrinkage and cracking in the brick-making pro- 
cess, yet is not so high as to interfere with the binding proj)erties of 
the clay. The clay is mined to a depth of 15 feet by hand shoveling 
into dump cars, which are hauled up an incline by a steam winch, to 
dump through a hop])er into a 10-foot dry pan. After screening, the 
fines pass to a ])ug-mill, then to an American Clay Machinery Co. 
auger machine e()uipi)ed with a Preese cutter. The oversize from the 
screen is returned to the dry pan. 

The brick are dried in the open without auxiliary heat. This 
requires an average of three weeks. P.iirning is done in open field 
kilns, usually Avith 18 arches, each kiln containing 590,000 brick. Heat 
is supplied by oil, with steam atomization. Firing requires five days, 
and cooling about three weeks. 

The plant operated three months during the season of 1925, producing 
about 1,500,000 brick. Twenty-eight men are employed when in full 
operation. See ))hoto No. 65. 

Bibl: State Mineralogist's Report XXI, ]). 505. 

Santa Margarita. Two miles south of Santa IMargarita is an extensive 
undeveloped deposit of red-burning shale. The deposit is easily 



214 



DIVISION OF MINES AND MINING 




p 



i 

E 
o 
y 



to 



8-^ 

o . 

Oo 



O o 

p. 

CO aj 

1—1 to 

c +-' 

S.2 

o 

|1 

|S 












?^ 

o 

O 



CLAY RESOURCES AND CERAMIC INDUSTRY 215 

accessible at a point 2.0 miles (by road) south of the center of 8anta 
]Marj;arita, where it lies in a broad belt between the state hij^hway and 
the Southern Pacific railroad for a distance of at least one-half mile. 
The strike of the beds is S. 25° E., and the dip is 75° NE. 

Two samples were taken. No. 216 was taken from a road cut, 2.0 
miles from Santa ]Mai'<>ai-ita. Sample No. 217 was taken from the same 
formation, 2.5 miles from Santa Mar<iarita, and 0.;] miles north of the 
northern boundary of the Santa Barbara National Forest. The test 
results are on page 827. Tlie material would be well suited for the 
manufacture of vitrified red-burned structural ware. 

Bibl (Clay resources of San Luis Obispo County) : State Min. 
Bur. Bull. 38, p. 255; Prel. Kept. 7, p. 95; State Mineralogist's 
Rept. XV, p. 679 ; XXT, p. 505. 

SAN MATEO COUNTY. 
General Features. 

San ]\Iateo County lies on the San Francisco Peninsula, south of 
San Francisco city and county. Its southern boundary adjoins Santa 
Clara and Santa Cruz mountains. Its area is 447 square miles, and 
the population is 36,781 (1920 census). 

Aside from a narrow strip of alluvial ])lain along the shores of San 
Francisco Bay, the entire county is mountainous, as the western spur 
of the Coast Range extends through the county. The jn-incijial 
geological formations exposed in the mountainous portion of the county 
are Franciscan (Jura.ssic) sandstones, jaspers, ser])entines, etc. ; Chico 
(Upper Cretaceous), Pliocene and Miocene sedimentary deposits, 
mainly sandstones and shales, and granite. 

The most important mineral jiroducts are cement, miscellaneous 
stone, and salt. Jasper, magnesium chloride, natural gas, petroleum, 
and jiotash are also ])roduced. Small amounts of barytes, chromite, 
diatomite, and quicksilver have also been found. 

Clay Resources. 

No high-grade clays have been reported in the county. Deposits of 
clay and shale suitable for brick making are ])lentiful. 

The only clay-working plant in the county is that of the West Coast 
Porcelain Manufacturers, described below. The Steiger Terra Cotta 
and Pottery Works, and the Baden Brick Company, mentioned in 
earlier reports, were dismantled many years ago. 

West Coast Porcelain Manufacturers. Henry Weiss, president and 
general manager ; Ed. Durant, jilant manager ; T. B. Gotham, superin- 
tendent and ceramist. The i)lant is near ^lillbrae station on the South- 
ern Pacific Railroad. Vitreous sanitary porcelain is the only product. 
The body, which contains 50% clay and 50% flint and feldspar, is 
made from English china and ball claj^, Tennessee ball clay, Ottaw^a 
or Illinois sand and feldspar from Campo, San Diego County. Alber- 
hill bone clay is used in the sagger mix, as the aluminous structural 
clay; lone clays as the binders. 

All of the ware is shajjcd by casting, and the sli]) room is one of the 
most modern and best equipi)ed in the West. Special precautions are 
taken to secure uniformity of grinding and proportioning and freedom 
from contamination. 



216 DIVISION OP MINES AND MINING 

The body is prepared by tlie dry-mix process. Tlu-ee .SO-li]). Crossley 
dry pebble mills are used for grinding the Ottawa sand and feldspar. 
Seven hours grinding is necessary for each batch of sand or feldspar. 
The English ball clay is passed through a disintegrator to crush it to 
less than § in. diameter. The Tennessee ball clay does not require 
])revious crushing. The dry pulverized materials are stored in bins 
from which they are weighed out for the casting slip batches. Three 
double casting slip blungers are used for the preparation of the slip, 
which weigrhs 80 oz. per pint. The discharge from the blungers is 
passed over a Ding magnetic separator to remove any particles of 
metallic iron, then through a 100-mesh screen, and finally to Crossley 
slip agitators below the floor of the slip room. From the agitators the 
slip is pumped to the casting room. 

A small blunger and a 70-leaf round-rail filter press are used to 
retreat the scrap body-mix from the casting and drying departments. 
This is necessary in order to remove the alkali which is added to all 
slips as a deflocculator, and which, if left in the rejected material, 
Avould build up in the casting slip to the point Avhere blisters would 
form on the ware during firing. 

The glaze batches are ground in a Crossley, style B pebble mill, 8 feet 
diameter and 5 feet 8 inches long, driven by a 20-hp. induction motor. 
When grouiul, the slip is passed through a 100-mesh screen, and is 
pumped into a Patterson single-action glaze agitator, where it is kept 
in suspension until drawn off for use. A magnetic separator is used 
to remove any particles of iron that might accidentally have been 
introduced into the glaze. 

The casting slip is piped to all parts of the casting floor, where the 
ware is cast in the usual manner in plaster molds. 

Waste-heat driers are used. After drying, the Avare is loaded into 
saggers in preparation for the biscuit firing. 

The firing equipment consists of two 366-ft. tunnel kilns, operated 
on a 48-hour cycle. The biscuit kiln is fired to a maximum of cone 11, 
which corresponds to 1205° C. on the recording pyrometer. After 
cooling from the biscuit kilns, the glaze is applied by dipping, and the 
ware is sent through the glost kiln, which is fired to cone 6, correspond- 
ing to 1150° C. on the pyrometer. Oil fuel, atomized with air, is used 
on both kilns. The capacity of the kilns is 400 pieces per 24 hours. 

Saggers are made by machine at the plant. Alberhill bone clay has 
proved a better structural clay in sagger manufacture than lone clay. 
The lone clay body burns too tight, and losses from cracking after 
repeated use are high, but used as a binder it is more or less satisfactory. 

The company has recently developed a line of crystalline-glaze art- 
ware, and many attractive shapes and color schemes are being produced. 

The plant has a well-equipped laboratory, and through careful tech- 
nical control the products of the plant are of remarkably high quality 
and free from defects. The plant employs 150 men. 

Bibl (Clay resources of San Mateo Count v) : State Min. Bur. 
Bull. 38, pp. 228-221), 255; Prel. Kept. 7, pp. 95-96. 



(LAY RESOURt'ES AND CERAMIC INDUSTRY 217 

SANTA BARBARA COUNTY. 
General Features.' 

Santa Barbara County consists of 2740 square miles, includino; the 
islands of San Mi<ruel. Santa Kosa, and Santa Cruz, which are located 
twenty miles off the coast. It is bounded on the north by San Luis 
Obispo County, on the east by Ventura County, on the south by the 
Santa Barbara Cliannel, and on the west by the Pacific Ocean. 

The population, accnrdinp- to the census of 1920, was 41,097, and is 
now estimated as over 50,000. The city of Santa Barbara, the county 
seat, with a population of over 30,000, lies on the shores of the channel. 
Santa Maria is the second community in Santa Barbara County and 
has a population of over 5000. 

]\Iuch of Santa Barbara County is hilly and mountainous; the Santa 
Ynez, a low range of inountains, follows the trend of the coast across 
the southei-n jiart of the county, and the San Rafael, a higher range, 
strikes througli the center of the county and extends almost to its nortli- 
ern limits. These mountains, with their foothills and spurs, impart to 
the whole county- a rugged and diversified aspect. 

The principal valleys are the Santa Maria, Los Alamos, Lompoc, 
Santa Ynez, and Cuyama. These fertile areas are well adapted for the 
growing of cereal crops and citrus fruits and cattle raising. 

The principal drainage systems of the county are the Santa Maria 
and Santa Ynez rivers. 

The county is traversed by the Southern Pacific railroad, which fol- 
lows the coast line, with branch lines from Guadalupe to Betteravia, 
and from Surf to Lompoc. The Pacific Coast railroad, a narrow-gauge 
line, runs from Port llanford, in San Luis Obispo County, through 
Santa IMaria to Los Olivos, with branches from Santa ]\Iaria to Bet- 
teravia and Sisquoc. Santa ^laria Valley railroad connects with the 
Southern Pacific i-ailroad west of Santa Maria and runs southeast 
through the Santa Maria Valley to Leonard. 

The coast route of the state highway enters the county north of 
Santa Maria, and runs the length of the county, connecting Santa Bar- 
bara city with Los Angeles and San Francisco. Different laterals from 
this railway afFnrd trnnsjiortation for auto trucks and stages to interior 
towns. 

Geology and Mineral Resources. 

The principal geological formations exposed in Santa Barbara County 
are Tertiary shales and sandstones, including those of Eocene, Miocene, 
and Pliocene age. Quaternary sediments also cover a large area, 
especially in the western part of the county. There is a small area of 
Franciscan (Jurassic) in the center of the county, and a larger area of 
Cretaceous (Undifferentiated) in the north-central part of the county. 

Santa Barbara County owes its position of fifteenth in the state in 
regard to its mineral output to the presence of productive oil fields 
within its boundaries. The total value of its mineral production during 

'Prom Tucker, W. Burling, Santa Barbara County: State Mineralogist's Kept. 
XXI, pp. 539-540, 1925. 



218 DIVISION OP^ MINES AND MINING 

the year 1026 was $2,583,548; of this amount the value of natural gas 
and petroleum was $1,772,678. 

Among its mineral resources, both developed and undeveloped, are : 
Asphalt and bituminoas roek, barytes, brick, chromite, copper, diato- 
maceous earth, gilsonite. jiold, gypsum, limestone and lime, manganese, 
mineral water, natural gas, oil shale, petroleum, sandstone and the 
stone industry. 

Clay Resources. 

Xo commercial deposits of high-grade clays have been found in the 
county. Common clay is fairly abundant, and several brick yards and 
a roofing tile plant are in operation. 

AnguJo Tile Company, Plant No. 1. R. F. Angulo and Sons, owners. 
Address P. 0. Box 128, Santa Barbara. This company has two plants 
for the manufacture of hand-made roofing tile and terrace tile. Plant 
Xo. 1 is on Central Avenue, between Modoc Road and the state highway, 
Santa Barbara, and Plant Xo. 2 is at Reseda, Los Angeles County (see 
under Los Aneeles Countv. At Plant No. 2 a local surface clav is 
mined from an area immediately adjoining the ]>lant. The plant is 
equipped with three kilns, fired with oil. 

L. L. Brentner. Carpinteria. The property is west of the coast 
highway, 14 miles north of Ventura, and four miles south of Carpin- 
teria. Ten acres were at one time under lease to the Builder's Supply 
Company of Santa Barbara, who operated a plant for the manufacture 
of common brick. It is understood that the proi)erty is now idle (1927). 
The clay beds are nearly vertical, have an east-west strike, and are 
about 200 feet thick. The material is a light-colored thin-bedded shale, 
with quartz, limestone, and sandstone boulders, which were i)artly 
removed by screening. A drag-line scrajjcr was used for mining. The 
plant is equipped with crushing machinery to deliver a 20-mesh product 
to the brick plant, which consists of a 14-ft. pug-mill and an auger 
machine, with a wire cutter. The brick were dried in the open and 
fired in oil-fired field kilns. 

Sample Xo. 3 was taken for testing, the results of which are on page 
348. The material is not of good quality for the manufacture of brick. 

Bibl: State Mineralogist's Rept. XXI, pp. 546-547, 1925. 



Muengenherg and WhitiJcer. R. ]\Iuengenberg and E. H. Whitiker, 
of 230 de la Guerra Street, Santa Barbara, are operating two of the 
brick yards formerly opei-ated by the Builder's Supply Company in 
Santa Barbara and Montecito. 

The Santa Barbara plant, formerly the Parker Brick Company, is 
on West Montecito Street, one-half mile from the Southern Pacific 
railroad tracks. Common red brick, hollow building tile, and drain tile 
are made from clays obtained from ]iits on the i)lant site and from 
other sources in the vicinity. The stiff-mud process is used. The ware 
is dried in the open, and fired in oil-fired field kilns. Samj^le Xo. 1 
Avas taken for test, the results of which are on ])age 338. Tlie sample 
was taken from the i)ug-mill, and is typical of the class of material 
available in the district, and for which the plant ha.s been designed, 
rather than being rej^resentative of a specific clay bank. 

The Toro Canyon plant, formerly the Toro Canyon Brick and Tile 



CLAY RESOURCES AND CERAMIC INDUSTRY 219 

Company, is in Torn Canyon, near IMontecito. There is an anii)U' sup- 
ply of plastic clay, interinintrled with blocks of soft, yellow sandstone. 
The clay is mined from a sliallow side-hill open cut with tractors and 
scrapers. Connnon red brick, hollow buildinji' tile, and roofin**' tile are 
made. Drying' is done under sheds and in the open, and oil-fired field 
kilns are used for firing. Sample No. 2 (see p. 338) was taken. 

Bibl: State Mineralogist's Repts. XV, p. 735; XXI, pp. 546-547. 

Bull. 38, p. 25(i. Prel. Kept. 7, p. 96. 

SANTA CLARA COUNTY. 
General Features. 

Santa Clara County lies in the west-central portion of the state. Tt 
is bounded on the north by San ^lateo and Alameda counties, on the 
east by Stanislaus aiul Pierced, on the south by San F)enito, and on the 
west by Santa Cruz and San ^lateo. The area of the county is 1328 
square miles, and the jiopulation is 100,588 (1920 census). The prin- 
cii)al towns are San Jose, Palo Alto, Santa Clara, and Gilroy, all of 
which lie in a broad valley between two ))arallel ranges of the Coast 
Range system of mountains. This valley is noted as one of the most 
productive fruit-growing sections in California. 

The g-eological formations that are most widespread in the county are 
Quaternary sediments in the valleys, and Franciscan (Jurassic), 
Cretaceous, Pliocene, and Pliocene formations in the mountains. 

The New Almaden district, about 15 miles south of San Jose, was for 
many years famous as a (quicksilver producer, but the production has 
declined in recent yeai's owing to the exhaustion of the mines. The 
following' mineral products are produced commercially : brick, clay, 
limestone, magnesite, mineral water, natural gas, petroleum, quicksilver, 
and miscellaneous .stone. Of these miscellaneous stone, brick, and 
quicksilver are the most important, in the order given. Occurrences 
of chromite, manganese, and soapstone are known. 

Clay Resources. 

No commercial dei)osits of high-grade clays are known in the county. 
Common clays suitable for the manufacture of brick and tile are abund- 
ant throughout the valley i)ortions of the county. On account of 
favorable manufacturing and marketing conditions, a number of clay- 
working plants have been established in and near San Jose and Santa 
Clara. Some of these ]ilants use common clay from extensive deposits 
along Coyote Creek within the city limits of San Jose. The clay bed 
is from 15 to 20 feet thick. 

Garden City Pottery Company.^ H. ]M. Stammer, president; D. 
Raymond, vice president ; N. J. Mahan, secretary. Office and plant at 
560 N. Sixth Street, San Jose. This com])any was established in 
1904, under the name of the Garden City Pottery. The products of 
the plant are flower pots and stoneware. Lincoln clay is used for the 
strneware, and a local red clay, from Coyote Creek, is used for flower 
])ot.s. The stoneware mix is prepared by grinding, washing, and filter- 
I)ressing-, followed by pugging. After shaping, the ware is dried in 
steam-heated drying; rooms for a period of three or four days. 



^Data obtained by D. R. Irving, Stanford University. 



220 DIVISION OF MINES AND MINING 

Firing: is done in four round down-draft kilns. Two of the kilns are 
20 feet, and the other two are 18 feet in diameter. They are fired 
with oil, which is atomized with steam. The stoneware is fired to 
2200° F. (about cone 5) in 72 hours, and the flower pots are fired to 
1800° F. (about cone 07) in 48 hours. 

The plant operates throughout the year and employs 30 men. 
Bibl : State Min. Bur. Bull. 38, p. 229 ; Prel. Rept. No. 7, p. 96. 

Gilroy Brick and Tile Company. Chas. Bolting, Gilroy. Mr. Bolting 
built and operated a small common brick plant for a few years on his 
ranch about one mile north of Gilroy, using a clay shale obtained from 
a deposit on the Redwood Retreat Road, about eight miles from Gilroy. 
The plant was not commercially profitable, and has been partly 
dismantled. 

Kartscho'ke Clay Products Compan]i. G. Kartschoke, president and 
manager. Plant at 1098 S. Third Street, San Jose. The principal 
products of the plant are sewer pipe, flue lining, and patent chimney 
pipe. The plant is also equipped to make machine-made roofing tile. 
The clays are obtained from banks along Coyote Creek, with the addi- 
tion of some clay that is purchased from the Yarn deposit in Amador 
County. 

The clays are ground in a dry pan and elevated to a double-shaft pug- 
mill, from which the mix passes to an American sewer pipe press. 
Drying is done in a building which is heated by steam during the win- 
ter. Four to five days are usually required for drying. 

The ware is fired in three oil-fired round down-draft kilns, 22 feet, 
26 feet and 28 feet in diameter, respectively. Cone 2 (1165° C.) is 
reached in 80 to 90 hours, the entire cycle, including setting and draw- 
ing, requiring about two weeks. 

Bibl: State Mineralogist's Rept. XIII, p. 618; State Min. Bur. 
Prel. Rept. 7, p. 97. 

J. B. King, of Skyland, P. 0., Wrights Station (Santa Cruz County). 
It is reported that there is a "fine, large deposit of pottery clay" on 
this property. No investigation was made. As the locality is relatively 
inaccessible, near the summit of the Santa Cruz Mountains, the clay 
would need to be of exceptional quality to be of commercial importance. 

Piatt's Premier Porcelain, Incorporated.'^ H. D. Melvin, president; 
A. A. Baker, vice president ; N. E. Wretman, secretary. Office and 
plant on Lafayette Street, Santa Clara. This company makes sanitary 
porcelain from a mixture of English china and ball clays, Arizona 
feldspar, and California silica. The feldspar and flint are received at 
the plant in pulverized form. The mixes are prepared by blunging and 
filter-pressing. The ware is shaped by the casting process, although 
hand-pressing was formerly used, and is dried in steam-heated rooms 
for a period of one week. Three 16-ft. round ui)-draft ('bottle') kilns 
are used for firing. These use oil fuel, atomized with steam. The biscuit 
ware is fired to cone 9 (1250° C.) in 36 hours, and the glost ware is fired 
to cone 8 (1225° C.) in 30 hours. Tlie jdant was idle during 1927, but 
expected to resume operations early in 1928. 

• Data obtained by D. R. Irving, Stanford Univer.sity. 



CLAY RESOURCES AND CERAMIC INDUSTRY 221 

EcmiUard Brick Company. C. Kciuillard, president ; R. C. Giroux, 
secretary. Office, Xi2 Plielan r>iiil(liii«i-, San Francisco. This company 
has operated a brickyard at IMcasanton, Alameda County, for many 
years, and has recently established a plant in San Jose, on Storey Koad, 
on the eastern edge of town. Common red brick are made from a 
local clay, nsin«i- open field kilns for firing. The plant is operated for 
about eight months during the year. 

San Jose Brick and Tile Company. J. J. Jainiesen, president; R. L. 
Richards, secretary-treasurer. Address P. 0. Box 274, San Jose. The 
plant is on Fruitvale Avenue, and the property comprises 85 acres. 
Common red brick is manufactured. The clay deposit consists of a 
30-ft. bed of red-brown plastic clay overlain by three to five feet of soil. 
The clay is mined and clelivered to the plant by a drag-line scraper. 

The plant is equipped with an E. M. Freeze K-B brick machine, 
which has a capacity of 75,000 brick per day and is driven by a 150-h.p. 
electric motor. An industrial ear system is used in the drying and 
kiln yard. Diying in open racks requires from seven to eight days. 
One round down-draft kiln and two down-draft continuous kilns are 
used for firing. Coal screenings are used as fuel. The firing schedule 
of the continuous kilns is as follows: three days Avater smoking, four 
days firing and ten days cooling. 

The plant is usually operated for nine months of the year, employing 
50 men, and using 345 h.p. of electric power. The average fuel con- 
sumption is 300 lb. of coal per thousand brick. 

San Jose Tile Companij. A partnership, consisting of L. W. Austin, 
D. W. Wallace, L. F. Wallace, W. D. Rice, and L. II. Bruns. The plant 
is at 333 S. Eighteenth Street, San Jose, on the banks of Coyote Creek. 
Hand-made floor, wall, and mantel tile are manufactured, using a red- 
burned body consisting largely of clay from the Natoma Clay Comi)any 
in Sacramento County. Local clay from Coyote Creek and some Lin- 
coln and lone materials are used to a certain extent. The equipment 
consists of a disintegrator and pug-mill, and a rectangular kiln, burn- 
ing oil. The kiln is equipped with a pyrometer. The firing period is 
from 40 to 48 hours, finishing at cone 5 (1180° C), or higher. 

An excellent market has been established for the ware, and the plant 
is expected to grow rapidly. 

8 & S Tile Company. A. L. Solon and F. P. Schemmel, owners. 
Office and plant at 1881 S. First Street, San Jose. This company 
specializes in the manufacture of decorative tile, both glazed and 
unglazed, from a huff, or red-colored body. Local clay from Coyote 
Creek is used in conjunction with Lincoln clay and lone sand. Biscuit 
re.iects and kiln dirt are used as grog. 

The clays are mixed in batches on the floor, fed to a Jeffrey swing- 
hammer mill, and elevated to a bin, from which they are fed by a disc 
feeder to a pug-mill. A INIuller auger is used for shaping all plain tile, 
whereas fancy tile is hand-pressed in plaster molds. Some dry-pressed 
tile are made at times. A specially designed waste-heat drier is used. 
To secure partial humidification, the drier is arranged so that the hot 
air can be retained in closed circuit. Drying requires three days. Two 
oil-fired round kilns are used. These are 18 and 22 feet in diameter, 
respectively. They are fired to cone 2 (1135° C.) in 48 hours. Cool- 



222 DIVISION OP MINES AND MINING 

ing: requires four days. Both kilns are ecinipped Avitli base-metal 
thermocouples. All j^lazed ware is biscuited first, then .ulazed. About 
eight men and six women are employed. 

SANTA CRUZ COUNTY. 
General Features.' 

8anta Cruz County borders on ]\Ionterey Bay and the Pacific Ocean, 
south of San Mateo County, and north of ^Monterey County. Its area 
is 435 square miles, and the population is 26,269 (1920 census). The 
oreater part of the county is rugged and mountainous. 

The geology of most of the county is described in U. S. Geological 
Survey, Santa Cruz Folio, No. 163, by J. C. Branner, J. F. Newsom, 
and Ralph Arnold. The principal sedimentary formations are of 
Miocene and Pliocene age. There is an extensive area of quartz-diorite, 
and smaller areas of metamorphic schist, marble, and limestone. 

The mineral production of the county includes cement, lime, lime- 
stone, and miscellaneous stone, and bituminous rock. 

Clay Resources. 

Common brick clays occur along the San Lorenzo River and at other 
points. In the early nineties, two brickyards were in operation near 
Santa Cruz, but these have long since been dismantled. Clay is being 
mined at Tank Siding, 1.8 miles southwest of Glenwood, and at Daven- 
port, for use in the manufacture of cement at the j^lant of the Santa 
Cruz Portland Cement Company, at Davenjjort. 

Bibl: State Mineralogist's Repts. X, p. 625; XII, p. 383; XIII, p. 
619; XVII, p. 234; XXII, pp. 78-79. Prel. Rejit. No. 7, p. 97. 

SHASTA COUNTY. 
General Features. 

Shasta County lies at the northern end of the Sacramento Valley. 
Redding, the county seat, is on the Shasta line of the Southern Pacific 
Railroad, 175 miles north of Sacramento, and is the principal rail- 
road and supply point for Shasta and Trinity counties. The Pacific 
highway connecting California anfl Oregon, traverses the county in 
a north and south direction, paralleling the Southern Pacific railroad 
in the Sacramento River Canyon. 

The area of Shasta County is 3858 square miles and the population 
in 1920 was 13,311. The southern ])ortion of the county adjacent to 
the Sacramento River is open and rolling, and is devoted to farming 
and stock raising. The northern and western ])ortions of the county 
are mountainous, and the eastern ])ortion is a succession of rising 
plateaus covered by recent volcanic flows. ]\Iost of the important 
mineral deposits of the county are confined to the western half. The 
Pit River, which joins the Sacramento River near Redding, is an import- 
ant source of hydro-electric ]iower. Timber is an important resource 
of the county, especially in the eastern portion. 

Shasta County is characterized by the variety of its geologic forma- 
tions, and the diversity of its mineral resources. Copper, gold, zinc 

'See Laizure, C. McK., Santa Cruz County : State Min. Bur. Rept. XXII, pp. 68-93, 
1926. 



CLAY RESOURCES AND CERAMIC INDUSTRY 223 

and iron aro the principal metals thai liave been produced in the 
county. The limestone resources are very extensive, but to date have 
not been exjiloited on a lar«re scale. Ext(Misive beds of low-«»rade 
lij,niile occur in the central part of the county. These have been 
investigated many times in the past, and an attempt is now being made 
to place them upon a sound commercial basis. 

Clay Resources. 

Tliere is at present no clay industry in the county. At various times 
in the past, brick yards have been operated at Redding and Anderson, 
to supply local needs, but these have been idle for many years. There 
is an abundant sui)ply of clay and silt suitable for common-brick 
manufacture in the flood plain of the Sacramento River south of 
Redding, and along other streams in the county. 

No commercial deposits of high-grade clays have yet been discovered 
in the county. It is possible that with the serious development of the 
lignite properties northeast of Oak Run, mainly in T. 33 N., R. 1 W., 
M. D. M., refractory clays may be encountered, as the lignites occur in 
the lone formation, which is the important source of terra cotta and 
fireclays in I^lacer and Anuulor counties. A small samjile of micaceous 
kaolin, slightly tinged with iron, was supplied by Mr. I. J. Johnson, 
of the Johnson Iron Works, Redding, but no data could be secured as 
to the source of this nuitcrial, excei)t that it was found on a property 
some 20 miles northeast of Palo Cedro. 

For convenience of reference, the following descrii)tions of common- 
brick clay deposits are abstracted from previous publications of the 
Bureau : 

State Mineralgist's Report XXII, p. 131, 1926; Prel. Rept. No. 7, 
p. 98, 1920. 

Holt and Gregg, J. N. Gregg, president, Kennett. A brick j)lant 
was formerly operated at Anderson, in Sec. 17, T. 30 N., R. 4 W., 
M. D. ]\I. The deposit was 15 feet thick. 

Block 29, Bedding Grant, 1] miles south of Redding. Clay bed six 
feet thick. A brick kiln was operated here many years ago. 

Bedding Brick and Tile Compamj f(n-mer]y ojierated a dei)osit on 40 
acres in Sec. 19, T. 31 N., R. 5 W., M. D. M., and made brick in small 
kiln at Redding. 

Bedding Homestead Deposit is on the Sacramento River east of 
Cottonwood. Deposit is a mile long by one-fourth mile wide and 
contains 30 feet of clay, covered by 15 feet of sand and gravel. Unde- 
veloped. No recent information available. 

Southern Pacific Company owns an undeveloped clay deposit in 
Sec. 19, T. 32 N., R. 4 W., M. D. M. 

In addition to the foregoing, a deposit of fireclay is reported in Sec. 
24, (34?) T. 34 N., R. 5 W., M. D. M., that was at one time operated 
by Holt and Gregg for use as kiln lining. No recent information since 
the report of 1920. 



224 DIVISION OP MINES AND MINING 

SISKIYOU COUNTY. 
General Features. 

Siskiyou County borders on the state of Oregon in a sparsely-settled 
mountainous portion of California. The total area of the county is 
6256 square miles, and the population (1920) is 18,500. The county 
is traversed by the Sliasta line of the Southern Pacific railroad. The 
principal industries of the county are lumbering, stock-raising and 
farming. The mineral industry of the county is not at i)resent of 
great importance, although in the past the county has been celebrated 
for its placer mines, and during the late war it was an important source 
of chromite. The geology and mineral resources of the county have 
been discussed in a recent report.^ 

Clay Resources. 

On account of the remoteness of the county from the centers of popu- 
lation and the small population within the county itself, none but 
exceptionally high-grade clay deposits could have commercial value. 
A deposit of 'pottery clay' 16 ft. thick has been reported- in Sec. 8, 
T. 43 N., R. 6 W., near Gazelle. A careful search for this deposit was 
made in August, 1925, and local inhabitants were questioned concern- 
ing it, but no knowledge of such a deposit could be obtained. The 
report probably refers to a deposit of yellow plastic clay that occurs on 
the pro})erty. A de])osit of fireclay in the roof of a coal mine in 
Sec. 26, T. 46 N., R. 6 W,, has also been reported ^ but could not be 
verified. The coal mine referred to is now inaccessible. 

Common brick clays occur in irregular alluvial deposits at various 
places in the county. Some of these, near Yreka, Etna Mills, and Fort 
Jones have been used in the past for producing brick for local use 
during the early construction periods of the larger towns in the county. 
None of the brick yards have been operated for many years, and have 
long since been dismantled. If at any time in the future it should 
become necessary to manufacture small quantities of red brick in the 
county, enough clay of satisfactory quality could probably be found, 
but it is unlikeh' that large deposits of uniformly good material will be 
encountered. 

For convenience of reference, the previous reports of the bureau on 
common clay deposits in Siskiyou County are summarized below, but 
as these reports are over 20 years old, the names of the men who were 
formerly associated with the deposits are omitted here, as few of them 
can now be found. 

T. 43 N., R. 9 W., M. D. M. Surface clay deposits were reported in 
Sec. 2, 11, 21 and 32, in the vicinity of Fort Jones, Green view, and 
Etna. These clays have been used for brick making. 

Sec. 27, T. 45 N., R. 7 W. Bricks were once manufactured from a 
reddish clay near Yreka. 

Near Montague a small quantity of brick clay has been found. 

Bibl : Cal. State Min. Bur. Bull. 38, p. 230 and 257, 1906 ; Prel. 
Rept. No. 7, p. 98, 1920 (a copy of the material in Bull. 38). 

' state Mineralogist's Report XXI, jip. 413-498. 1925. 
= Prel. Rept. No. 7, p. 99. 
' Op. cit., p. 98. 



CLAY RESOURCES AND CERAMi:' INDUSTRY 225 

SOLANO COUNTY. 
General Features.' 

Solano County i-adiates in a northeasterly direction from San Pablo 
Bay, an arm of San Francisco Bay. Its area is 822 square miles, and 
the jiopulation is 40,602 (1920 census). About 80 per cent of the 
land is arable and the balance is mountainous. Cretaceous and Ter- 
tiary sediments, and late Tertiary (probable) lavas are found in the 
mountainous portion of the county. The rest of the county is covered 
with Recent alluvium. 

Among the mineral resources of Solano County are cement, clay, 
fuller's earth, limestone, mineral water, natural ji'as, onyx, quicksilver, 
salt and miscellaneous stone, llecent production has been confined to 
cement, miscellaneous stone, mineral water, onyx and travertine. The 
only cement plant in the county was closed down in November, 1927, 
aiul is available as a stand-by plant. 

Clay Resources. 

Common brick clays are abundant in the argicultural section of the 
county. A number of clay-working plants, including a pottery at 
Renicia and brick and tile plants at Vallcjo, were active a number of 
years ago. 

Steiger Brick and Tile Company (formerly the Vallejo Brick and 
Tile Company). Plant two miles northwest of the center of Vallejo. 
This is the latest attempt to operate a bricln^ard in the county, and 
operations were discontinued in 1923. The plant is equipped for the 
manufacture of brick and hollow tile. The clay deposit is a yellow 
siiale, an analysis of which is reported by Laizure- as follows: 

Loss on ignition 8.03% 

Silica 57.83% 

Alumina 19.52% 

Iron oxides 7.46% 

Calcium oxide 1.24% 

Magnesium oxide ^ 2.06% 

Alkalies (by difference) 3.86% 

100.00% 

Clav from a bank at the base of the hills near Goodvear Station was 
utilized about 20 years ago in a pottery. 

Bibl : State Mineralogist's Repts. VIII, p. 631 ; XIII, p. 619 ; XIV, 
]). 300; XXIll, pp. 204-205. State Min. Bur. Bull. 38, p. 258. 
Prel. Rept. No. 7, p. 99. 

SONOMA COUNTY. 
General Features.' 

Sonoma County is situated north of IMarin County and San Pablo 
Bay, extending eastward from the Pacific Ocean, which it borders for 
50 miles, to the crest of the Coast Range, which forms the boundary 
.separating it on the east from Lake and Napa counties. Mendocino 
County bounds it on the north. The land area of the county is 1577 

' See Laizure, C. McK., Solano County : State Mineralogist's Rept. XXIII, pp. 
203-213, 1927. 

= Op. cit., p. 204. 

3 From Laizure, C. McK., Sonoma County : State Mineralogist's Rept. XXII, pp. 
327-329, 1926. 

15—54979 



226 DIVISION OF MINES AND MINING 

square miles, and tlie poi)ulation is 51,990 (1920 census). Tliere are 
no ini{)rove(l harbors on the coast side, but water shii)i)ing facilities are 
available in the southern portion, which borders the bay. The North- 
western Pacific railroad traverses the county from south to north 
throufih the central valley, with branch lines into Sonoma Valley, to 
Sebastopol and to the Russian River region around Guerneville, Dun- 
can Mills and Cazadero. A narrow-gauge branch also extends from 
Marin County northward through Valley Ford to ]\Ionte Rio in the 
western part. A line of the Southern Pacific railroad from Xapa 
Junction in Xapa County traverses the Sonoma Valley and terminates 
at Santa Rosa. The Petaluma and Santa Rosa electric system also gives 
service to the southern portion of the county. The paved 'Redwood 
Highway' of the state system closely i)arallels the Northwestern Pacific 
railroad through the county. Its main laterals are also paved or well- 
kept graveled roads. 

The county produces a great variety of agricultural products, and 
dairying and stock-raising are important sources of wealth. Its min- 
eral deposits have been exploited more or less continuously since the 
sixties, and although it can scarcely be classified as a 'mining' county, 
metals and nonmetallic minerals exceeding $11,000,000 in value have 
been produced to date. Its resources are still far from exhausted. 

Many health-giving mineral springs are found here, and its resorts 
have made the county one of the favorite playgrounds of central 
California. 

Situated in the midst of the Coast Range, its topographic features 
include level valleys, Ioav rolling hills and rugged mountains, with deep- 
cut canyons. The drainage of the southern portion is to the bay, 
while that of the northern two-thirds is to the Pacific Ocean, chiefly by 
the Russian River and its tributaries. The main valley area, beginning 
at the bay, extends through the center of the county for about 60 miles, 
with an average width of 25 miles, but narrowing toward the northern 
end. Numerous smaller valleys separate the lesser spurs and ridges of 
the main range. 



"^f?^ 



Geology. 

Sonoma County is not covered by any of the Ignited States Geological 
Survey Folios, and the geologic literature on this area is fragmentary. 
The general geology has been described in part by Osmont,^ and bj' 
Vander Leek,- in its relation to possible oil production. The geology 
of the quicksilver ore deposits has also been covered in considerable 
detail by various writers. 

As shown on the State Mining Bureau's geological map of the state, 
the Franciscan rocks of the Coast Range cover probably three-fourths 
of Sonoma County, extending in a broad belt from the ^larin County 
line northwesterly the entire length of the county and beyond. This 
belt of metamorphic rocks widens toward the north. It consists mainly 
of sandstone, with smaller amounts of limestone, slates, cherts, schist, 
and much serpentine. Bordering the coast from Salmon Creek north, 
is a belt of Cretaceous sandstone and shale a few miles in width. Ter- 
tiary sedimentary rocks are exposed in a small area around Valley 

' Osmont, V. C, A Geological Section of the Coast Hanges North of San Francisco : 
Bull. Dept. of Geol.. University of California, Vol. 4, No. 3, pp. 39-87. 

- Vander Leek. Lawrence, Petroleum Resources of California : State MJn. Bur. 
Bull. 89, pp. 36-38. 



CLAY RESOURCES AND CERAMIC INDUSTRY 227 

Ford. The main valley area is conii)Osed of Quaternary sands, frravels, 
and clays aloii^' the Russian River from Cloverdale to Ilealdsburg. 
These foi-mations nai'i-ow at Wiudsoi- and then widen a^ain between 
Forestville anil Santa Rosa and continue south throutrli Sebastopol and 
Cotati nearly to Petaluma. The lowlands area around the mouth of 
Petaluma Creek and Sonoma Creek is also of Quaternary a<ie. Most of 
Soiumia Valley, the Sonoma Hills and the area surroundin<r Santa 
Rosa on the east and north is made up of Tertiary sediments consisting' 
of fine and medium sands, clay and shale. Late volcanic lavas cover 
a considerable area in the nei<ih])oi'hood of ^Mount St. Helena. They 
also ap])ear alon<»: the eastern boundary of the county, on the west side 
of Sonoma Valley, and near Petaluma. The lavas are mainly andesitic, 
but in places jrrade into basalt. Volcanic tutfs are found interbedded 
with the Tertiai-y sediments at many points. 

Amonji' Sonoma County's mineral resources are chromite, clay, coj)- 
per, jii-ai)hite. diatomite, magnesite, manganese, marble, mineral i)aint, 
mineral water, (piicksilver, and miscellaneous stone. Of these, miscel- 
laneous stone, (piicksilver, mineral water, ]iottery clay, building stone 
(tuff) and manganese ore were produced in 1925. 

Clay Resources. 

There has been in the past a considerable out|)ut of brick and clay 
in Sonoma County, but no clay-working plants are active at present. 
Common clays are sufficiently abundant for all probable needs of the 
county. 

A number of dejiosits of high-grade clay have been reported from 
time to time, but only one of these, the Weiss deposit, has been developed 
sufficiently to be of interest. 

Beltane. Sample No. 197 (see p. 291) was taken from a deposit that 
is exposed in a cut on a side road, 1.3 miles northwest of the state 
highway. The side road branches from the main highway at a point 
0.5 mile north of Warfield Station. The deposit is probably near the 
eastern edge of Sec. 2, T. 6 N., R. 6 W., M. D. M., about two miles east 
of Beltane Station. The clay is buff-burning and refractory. The 
extent of the deposit and its ownership wei*e not determined. This 
should not be confused with the Weiss clay, described below, which 
i.s sometimes known as 'Beltane clay.' 

Weiss Deposit. J. II. Weiss, Glen Ellen, owner. This is a deposit 
of white, moderately i)lastic, kaolin fireclay, in Sec. 3, T. 6 N., R. 6 W., 
M. D. M.. less than a mile by road east of Beltane station on the South- 
ern Pacific. The de])0sit has been worked at various times in the past, 
and over 2000 tons have been shipped to clay products manufacturers 
and to the Santa Cruz Portland Cement Company for experimental 
purposes. Five cars were mined and shipped in June, 1925, by Frank 
A. Asbury. lessee, of 753 Banning Street. Los Angeles, and was tried in 
several fire-brick plants in the Los Angeles district, notably by the 
St. Louis Fire Brick and Clay Company. 

The appearance of the deposit and the extent of development work is 
shown in photo No. 66. The tunnel is said to be 100 feet long, with 
various secondary workings, but it is now caved near the portal. Bor- 
ings from the floor of the pit are said to have encountered clay of 
quality equal to that exposed in the workings, to a depth of 20 to 30 



228 



DIVISION OF MINES AND MINING 



feet. There is a smaller abandoned pit 100 feet to the east, in which 
clay of a similar nature is exposed. 

The origin and structural relations of the deposit Avas not definitely 
determined, but all available evidence points to the theory that it is an 
alteration in place of a flat-bodded, fine-grained aplitic rock. The 
overburden of several feet of soil, and the thick vegetation make tracing 
of the clay beyond the development faces difficult. 

About 400 yards to the north, and at a slightly higher elevation, is 
a prominent exposure of a rock containing quartz and a high propor- 
tion of feldspar. Some of this rock has been mined from an open cut, 
and the exposed bank is over 40 feet high. The rock has been tried as 
a fire-brick grog by several plants. Near the top of the bank, the rock 
is similar in color and aggregation to the clay from the pit to the south, 
but is hard and non-plastic. The more typical rock from the lower 
part of the bank closely resembles a chert. It is harder than steel, has 




Photo No. 66. Weiss clay deposit, facing noi-thwest. Near Glen Ellen, Sonunia 
County. (Samples No. 194 and 195.) 

a dull waxy luster, and contains isolated quartz and altered feldspar 
crystals, and scattered discontinuous veinlets of quartz. 

Sample No. 194 is a general sample from the clay pit. Sample 
No. 195 is a selected sample of the whiter clay from the pit and from 
the tunnel, near the portal. It represents from 10% to 15% of the 
clay exposed in the workings. The test results are on page 262. 

Bibl: State Mineralogist's Reports VIII, p. 635; XII, p. 384; 
XIV, pp. 316-318; XXII, p. 332. Bull. 38, p. 258; Pre). Kept. 
7, p. 99. 

STANISLAUS COUNTY. 
General Features.' 

Stanislaus County is situated in the San Joaquin Valley between San 
Joaquin County on the northwest and Merced on the southeast. It is 

' From Laizure, C. McK., Stanislaus County : State Mineralogist's Rept. XXI, pp. 
200-201. 1925. 



CLAY RESOURCES A.n'D CERAIMIC INDUSTRY 229 

bounded on the northeast by Calaveras and Tuolumne counties, and by 
Santa Clara on the southwest side. Stanislaus County contains 1486 
scjuare miles, and its population is 43,557 (1920 census). The pfreater 
part of its acreage is arable, and about one-half is capable of irrif^ation. 
The various branches of agriculture and stock-raising are the princi})al 
sources of wealth. 

The county extends across the San Joa(iuin Valley in a northeasterly 
direction from the summit of the ]\Iount Diablo Range on the west to 
the foothills of the Sierra Nevadas on the east. The central portion is 
composed of unconsolidated sands, gravels and clays. Bordering this 
formation on the northeast, with the line of contact a little above Oak- 
dale and Waterford, is a belt of older Tertiary clays, shales and sand- 
stones. This Tertiary belt extends to and comes in contact with the 
slates, limestones and other rocks of the Jurassic along a line which 
closely follows the northeastern boundary of the county. On the south- 
west, the low foothills of the Coast Range are made up of Cretaceous 
sandstones and shales. The extreme western portion is rugged and 
composed of Franciscan formations, typical of the Coast Range ; con- 
sisting of altered slates, cherts, massive sandstone, schists and serpen- 
tine. Deposits of magnesite, manganese, and quicksilver occur in this 
area. 

Gold has usually been the chief mineral product of Stanislaus County, 
but gold was exceeded in value in 1918-1919 b.y manganese, and in 
1921-1923 by miscellaneous stone. Gold, platinum, and silver are 
obtained mainly by dredging. Quicksilver and manganese are other 
metals found here also. Among its nonmetallic resources are clay, 
ocher, magnesite, silica, and miscellaneous stone, including crushed 
rock, gravel and sand. Other minerals occur, but the deposits in most 
eases have not been sufficiently developed to determine their commercial 
value. 

Clay Resources. 

Deposits of common clay, suitable for the manufactui'c of common 
brick, occur abundantly in the county, and have been worked at various 
times in the past near Modesto, Grayson, Newman, and Patterson, but 
there have been no recent operations. 

The Craycroft brickyard at Modesto operated between 1908 and 1916, 
but is now dismantled. In 1918 and 1919 Martin Kelch made brick 
from a clay deposit having a maximum thickness of 20 feet, on the 
Waterford road, about one mile ea.st of ]Modesto. 

No deposits of high-grade clay are known to occur in the county. 
The Cummings Ranch deposit, described below, has been noted in 
various reports of the Bureau. On investigation, it was found to have 
little or no commercial value. 

Cummings Ranch Clay Deposit. On the property of J. H. Cum- 
mings of Patterson, in Sec. 20 and 21, T. 5 S., R. 7 E., M. D. M., is an 
undeveloped deposit of hard, white clay-shale. The deposit occurs 
near the edge of the foothills west of Patterson, near the ranch house 
of W. J. Hammond. The deposit is exposed on the hillside 200 yards 
northwest of the ranch house. The total distance by road from Patter- 
son is 5.9 miles. The shale occurs in a bed from 10 to 15 feet thick 
haA'ing a strike of N, 50 W., and dipping 45° NE. The overburden of 



230 DIVISION OF MINES AND MINING 

shale, sandstone and soil varies from a few feet to over 15 feet in 
thickness. 

Sample No. 205 was cut from a five-foot portion of the bed that was 
whiter in color than the rest. The test results are on page 299. 

Bibl (Clav resources of Stanislaus County) : State Mineralogist's 
Kepts. XVII, p. 253, and XXI, pp. 204-205; State Min. Bur. 
Prel. Kept. 7, p. 99. 

SUTTER COUNTY. 
General Features. 

Sutter County lies north of Sacramento County, mainly between the 
Sacramento and Feather rivers. Its area is 608 square miles, and the 
population is 10,115 (1920 census). 

The outstanding topographic and geologic feature of Sutter County 
is the ]\Iarysville Buttes, which occupy a circular area about 10 miles 
in diameter in the north-central portion of the county, and rise to a 
maximum elevation of 2128 feet above sea level. The rest of the county 
is flat and is covered with deep alluvial soil. The Buttes consist of a 
core of andesite with intrusions of rhyolite surrounded by upturned 
lone (Eocene) sedimentary strata overlain by andesite tuff and 
breccia.^ The mineral production of the county is practically nil, and 
consists principally of crushed rock. 

Clay Resources. 

Clay beds of considerable extent have been reported to occur in the 
sedimentary Eocene strata of the Marysville Buttes. A reconnaissance 
of the region was made by the author in August, 1925, but no further 
information could be obtained, even after considerable search and local 
inquiry. 

Bibl: State Mineralogist's Kept. XV, p. 258; State Min. Bur. Prel. 
Kept. No. 7, p. 100. 

TEHAMA COUNTY. 
General Features. 

Tehama County is in the upper jiart of the Sacramento Valley. It 
extends east to the summit of the Sierras, and west to the crest of the 
Coast Range. Its area is 3166 square miles, and the population is 
2551 (1920 census). The Sacramento River flows through the center of 
the county, from north to south. 

The eastern half of the county is covered with sheets of lava, which 
had their origin from and around Lassen Peak. The central part of 
the county shows an extended plateau of gravels, sands and clays, 
which extend to the serpentines and metamorphic rocks of the Coast 
Range. 

Among the mineral resources of Tehama County are brick, chromite, 
copper, gold, manganese, marble, mineral water, salt, and miscellaneous 
stone. Brick and miscellaneous stone are the only commercial prod- 
ucts at i)resent. 

'Turner, H. W.. and Lindgren, W., Marvsville Folio No. 17. U. S. Geol. Surv., 1895. 
Lindgren. W.. U. S. Geol. Surv. Prof. Paper No. 73, pp. 2.3-25, 1911. 
Watt.s, W. L., Cal. State Min. Bur. Bull. 3, pp. 9-10. 1894. 
Cooper, J. G., Cal. State Min. Bur. Bull 4, pp. 36-45, 1894. 

Dickerson, R. E., Bull. Dept. of Geol., Univ. of Calif., Vol. 7, No. 12, pp. 257-298; 
pi.';. 11-14, April, 1913. 



CLAY RESOURCES AND CERAMIC INDUSTRY 231 

Clay Resources. 

Common brick clays are abundant in the Sacramento Valley portion 
of the county, especially near the river. A brickyard has been operat- 
in<r intermittently at Red l>lutt' for manv years. 

Banks of clay of fine quality are reported in the Flounwij di.strict.' 
Plournoy is in T. 24 N., R. 5 W., about fourteen miles west of the 
Southern Pacific railroad at Corning. iVo investigation was made of 
this occurrence. 

O'Connor Brotlicrs liricki/ard. Address, Red Blutf. The clay 
deposit and brickyard are on the Reed Tract, in Sec. 29, T. 27 X., R. 
8 \V., M. D. M. The deposit covers an area of over 19 acres, and is 
from 8 to 12 feet thick,, underlain by gravel. The soft-mud process is 
used, a small brick ]iress being ojierated by horse power. The brick 
are fired in open field kilns. The plant is operated intermittently to 
supply the local demand. 

Bibl : State Mineralogist 's Rept. XV, p. 260 ; State Min. Bur. Bull. 
38, pp. 258-259 ; Prel. Rept. 7, p. 100. 



TULARE COUNTY. 
General Features. 

Tulare County is in the southern San Joaquin Valley, and is bounded 
on the north by Fre.sno, on the ea.st by Inyo, on the south by Kern, and 
on the west by Kings County. It has an area of 4856 square miles, and 
the population is 59,0.'U (1920 census). 

The western half of the county lies in the San Joaf|uin Valley, and 
the eastern half is in the Sierra Nevada, culminating in a number of 
peaks along the summit at elevations exceeding 14,000 feet above sea 
level. The rocks in the mountains are mainly granites and other ])lu- 
tonics, whereas the valley is covered with Quaternary sediments. Vari- 
ous metamorphic and sedimentary rocks are found in the foothills. 

Climatic, soil and water conditions in the foothills and in the San 
Joaquin Valley section of the county are especially favorable to the 
growth of citrus fruits. This and other agricultural pursuits, includ- 
ing stock raising and dairying, are the principal industries of the 
county. 

The mineral resources of the county include brick, clay, copper, feld- 
spar, graphite, gems, limestone, magnesite, marble, quartz, glas.s-sand, 
soapstone, miscellaneous stone, and zinc. The commercial mineral 
products are brick, granite, lime, limestone, magnesite, natural gas, 
and miscellaneous stone, of which magnesite and granite are the most 
important. 

Clay Resources. 

Common clay of good quality for the manufacture of red-burned 
structural ware is plentiful in the valley and foothill section of the 
county. One brickyard has been in operation for a number of years. 

A deposit of buft'-bui-ning refractory clay has been found eight miles 
southeast of Ducor, but has not been developed commercially. See 
under Sears Clay Deposit. 

'Clay-Worker, August, 1926, p. 131. 



232 DIVISION OF MINES AND MINING 

Sears Clay Deposit. W. A. Sears, of Porterville, owner. Eight 
miles southeast of Diicor, in Sees. 26, 27, 35, T. 24 S., R. 28 E., M. D. M. 
This locality was visited in September, 1925, but the author was unable 
to meet Mr. Sears, or to find the deposit by personal search or by inquiry 
among residents in the locality. Later, ^Ir. Sears sent a number of 
samples of clav from the property. These were tested under numbers 
283-A, 283-B, 284, and 285. See pages 314, 316, and 282. A descrip- 
tion of the deposit was given in Preliminary Report No. 7, p. 100, and is 
quoted below : 

"The clay bearing strata extend about one-half mile south of White River and 
about two miles in length along the south bank of the river. An overburden of 
gravel and clay 6 to 8 feet thick overlies a bed of white and blue plastic clay. A 
number of small cuts have been made along the south bank of the river. These pits 
show a white clay 6 to 8 feet thick overlying a blue plastic clay. The strata of 
clay beds have a general northwest strike. The development of this deposit has 
been only superficial, so the depth of the clay bed has not been determined. The 
clay is suitable for tile, sewer pipe, fire brick, vitrified brick and terra cotta." 

8. P. Brick and Tile Co. W. D. Trewhitt, president ; H. W. Shields, 
secretary-treasurer ; H. G. Hayes, superintendent. General office. 435 
Rowell Building, Fresno. The plant is three-quarters of a mile south 
of Exeter, in Sec. 14, T. 19 S., R. 26 E., M. D. M. The property com- 
prises 20 acres, all of which is underlain by workable clay to a depth 
of 12 to 18 ft., underlain by coarse gravel. The products of the plant 
are common brick and hollow tile. 

The clay is mined by a i-yd. electric shovel, having a capacity of 
200 tons per eight hours. The clay is passed through a roll disinte- 
grator, from which it is elevated, screened, and passed to an American 
pug-mill and auger machine, eciuipped with a Freese cutter. Some 
of the ware is dried under sheds, and some in a waste-heat drier. The 
drying sheds have a capacity of 550,000 brick, and drying is usually 
completed in three weeks. The waste-heat drier has a capacity of 
135,000 brick, and the drying period is three days. 

The brick and tile are tired in open-field kilns. The fuel is oil, 
atomized with steam. The firing period is 5i days, and the kiln turn- 
over cycle is 12 days. Two round down-draft kilns are available, but 
are not used, as they are more expensive to operate than the field kilns. 

The capacity of the plant is 8,000,000 brick, or the equivalent volume 
of brick and hollow tile, per year. 

Valencia Heights Shale Deposit. C. H. Weed, of Porterville, owner. 
The deposit is six miles east of Porterville. in Sec. 34, T. 21 S., R. 28 E., 
M. D. M., and consists of black clay shale, almost a slate. The shale 
is 1500 to 2000 feet in width, and cuts through a serpentine belt. The 
strike of the beds is northwest and the dip is 75° SE. Sample No. 206 
was taken from a road cut, 5.3 miles from Porterville. The test results 
are on page 327. 

Bibl: State Min. Bur. Prel. Rept. 7, p. 101. 

Former Operations. 

The Pioneer Brick Company and the ]\IcKnight Firebrick Company, 
mentioned in Preliminary Report No. 7, pp. 100-101, are out of business. 



CLAY RESOURCES AND CERAMIC INDUSTRY 233 

VENTURA COUNTY. 
General Features.' 

Ventura County is bounded on tlie north by Kern County, on tlie 
east by Los Angeles County, on the south by Los Angeles County and 
the Pacific Ocean, and on the west by Santa Barbara County. The total 
area is 1878 square miles. The population as shown by the census of 
1920 was 28,724. 

The city of Ventura, originally called San Buenaventura, is the 
county seat, and is located on the shores of the Santa Barbara Channel. 
The cities of Oxnard, Santa Paula, and Fillmore are next in importance. 

Ventura County is essentially an agricultural and stock-raising 
county. The increasing ])roduction of petroleum in the i)a.st few years, 
however, is rapidly bringing it forward on the list of mineral-producing 
counties. 

The northern portion of the county is characterized by the converg- 
ence of several important mountain ranges, which make of it a high and 
rugged region. The moi'e mountainous and rugged parts of Pine Moun- 
tain and Topatopa Mountain form what is considered one of the rough- 
est and most inaccessible regions in California. Its lofty peaks range 
in elevation from 6000 to 9000 feet. To the northwest extend the San 
Emigdio Mountains, which form the connection between the Coast 
Range and the Sierra Nevada Mountains. To the west extend the San 
Rafael Mountains, while farther southward the Santa Ynez Mountains 
diverge from this group, running westward through Santa Barbara 
County. 

The southern part of the county is characterized by a series of 
]iarallel folds, the axes of which lie east and west, forming low moun- 
tain ranges of no great continuity. The principal valleys are Santa 
Clara, Ojai, Simi, and Las Posas. 

The two principal drainage systems of the county are the Santa 
Clara River and the Ventura River. Next in importance, but sub- 
ordinate to these is Calleguas Creek, which drains the Simi and Las 
Posas valleys. 

The county is traversed by the Southern Pacific railroad, with a 
branch line from Ventura to Ojai. At Montalvo, five miles east of 
Ventura, the main line divides into two branches, one going to Los 
Angeles via Las Posas and Simi valleys, the other through the Santa 
Clara Valley, joining the San Joaquin Valley line at Saugus. 

With the exception of the higher mountainous areas, the county is 
easily accessible by roads, the main arteries being paved. Access to 
the gold and borax districts is obtained over the state highway from 
Bakersfield to Los Angeles via Tejon Pass. 

Mineral Resources. 

Ventura was the fourth county in the state in respect to the value of 
its mineral production in 1926. Petroleum and natural gas are the 
principal products. The only other products, in 1926, were miscel- 
laneous stone, brick, and clay. Undeveloped resources include asphalt, 
borax, diatomite, gypsum, limestone, mineral water, mineral paint, 
molding sand, phosphates, and sandstone. 

' From Tucker, W. Burling, Ventura County : State Mineralogist's Report. XXI, pp. 
223-225, 1925. 



234 DIVISION OF MINES AND MINING 

Geology. 

The rocks of the Ventura rejiion fall into three classes : a meta- 
morphic aud granite complex, which is commonly referred to as the 
'basement' complex, a series of sedimentary rocks, and a series of 
igneous extrusive and intrusive rocks. 

The metamor])hic rocks are all of ])re-Jurassic age and have been 
intruded by granite that is probably of the same age as that of the 
Sierra Nevada, which is considered to be late Jurassic or early 
Cretaceous. 

The sedimentary rocks, which in this region form the greater per- 
centage, range in age from Ui)i>er Cretaceous to Recent. 

The igneous rocks are practically all of Miocene age and are mainly 
andesite, dacite, basalt, andesite breccia, and associated mud flows. 

Clay Resources- 
Common clays are sufficiently abundant in Ventura County to serve 

all purposes. Two brickyards are operated as needed to supply the 

local market. 

No high-grade clays have been reported in the county. 

Anderson and Hardison. This is a common brick ])lant, 2.7 miles 
north of Santa Paula, on the Ojai Valley road. The clay is obtained 
from an extensive deposit of sandy clay and is mined by a tractor- 
drawn scraper. The clay is prepared by crushing and screening, and 
the brick are .shaped by dry pressing. So far as known, this is the 
only brickyard in California using the dry-press process of making 
common brick. Gas-fired field kilns are used. 

Sample No. 6 was taken for testing. The results are on page 389. 

Bibl: State Mineralogist's Kept. XXT, p. 237. 

People's Lumber Company. C. E. Bonistell, general manager. Office 
in Ventura. Clay pit and brickyard on the Ventura Avenue road, two 
miles north of Ventura. The clay is mined from an extensive deposit 
of Pliocene (Fernando ?) age, which is also utilized as an oil-well mud. 
Two varieties of clay are found : a yellow clay, .sample No. 4, p. 338, 
which is considered best for use in making brick, and a bluish clay, 
sample No. 5, p. 339, which is more fine-grained and plastic, and is 
especially desirable for use in the oil fields. Common brick, red 
ruffled brick, drain tile, roofing tile, and hollow building tile are made, 
by the stiff-mud ])rocess. Open field kilns are used for firing, and 
natural gas is available as fuel. 

Bibl: State Mineralogist's Repts. XV, p. 759, and XXI, pp. 236- 
238. Bull. 38, p. 259 ; Prel. Rept. 7, pp. 101-102. 



YOLO COUNTY. 
General Features. 

Yolo County is in the Sacramento Valley, bounded by Sutter on the 
east and Colusa on the north. Its area i.s 1014 square miles, and the 
population is 17,105 (1920 census). The western edge of the county 
is in the foothills of the Coast Range, and the rest of the county is in 
the basin of the Sacramento River. 

The only commercial mineral resource at pre.sent is miscellaneous 



CLAY RESOURCES AND CERAMIC INDUSTRY 235 

stone. Quieksilver was at one time produced. Deposits of iron and 
sandstone have been noted. 

Clay Resources. 

Common hi-ick clay is abundant near Winters, Woodland, and Capay. 
Small (juantities of brick Avere made, chiefly at Woodland and Winters, 
ill the eighties, usinji' deposits of clay and clayey k)ara. 

Bibl: State Mineralooist's Kept. X, p. 791; XIV, p. 367. State 
Min. Bur. Bull. 38, p. 25!) ; Brel. Kept. 7, p. 102. 

YUBA COUNTY. 
General Features. 

Yuba County lies in tlu^ north-central part of the state and borders 
the east side of the Feather Kiver. It is bounded on the northwest by 
Butte and Plumas counties, on the southeast by Placer and Nevada 
counties, and on the east by Sierra County. Its area is 625 square 
miles, and the i)opulation is 10,375 (1920 census). 

Since its boundaries extend from the floor of the central valley of 
California to the middle wester-n slope of the Sierra Nevada JMountains, 
Yuba County includes diversified topography and climate. 

Geology.' 

The general geology of Yuba County is similar to that in Nevada and 
Placer counties. The main central portion of the county consists gen- 
erally of gabbro-diorite and granodiorite, which in turn grade into 
metamoi-phic. amphibolitic rocks. Schists and slates in ])laces overlie 
the igneous rocks and arc intruded by serpentine in the northern part 
of the county. Alluvial sands and gravels cover the entire western 
portion of the county, while auriferous gravels, in i)laces, lie along the 
old channel courses. 

The areal geology of Yuba County has been covered by U. S. Geo- 
logical Survey Folios No. 17, 18 and" 43. 

Yuba County is still an imj^ortant producer of gold, which is recov- 
ered by dredging and hydraulic mining. Other mineral products are 
miscellaneous stone, silver, natural gas, and i)latinum. 

Clay Resources. 

High-grade clay in small quantities has been mined from the J. F. 
Dem]isey Kanch (see below) near Smartsville. Common clays suitable 
for tlie manufacture of red-burned structural ware are plentiful in the 
vicinity of IMarysville. 

Dempsey Ranch Kaolin Deposit. A. deposit of kaolin fire clay occurs 
on the ranch of J. F. Dempsey, in the E| of Sec. 3, T. 15 N., R. 6 E., 
M. D. M., 2 miles southeast from Smartsville. The clay occurs as irreg- 
ular bunches exposed in small chamber workings at the end of a 100- 
foot tunnel. The clay was evidently formed by the alteration in place 
of diabase or a similar intrusive rock which penetrates the serpentine 
mass of the hill in which the deposit occurs. The clay is badly con- 
taminated with limonitic iron in most of the exposed workings, but 
occasional bunches of 5 to 10 tons can be found that are quite free from 

1 From State Mineralogist's Rept. XV, p. 420. 



236 DIVISION OF MINES AND MINING 

iron. It is doubtful if a commercial quantity of white kaolin could be 
found. 

J. V. Chown of Oakland at one time held a lease on the property, 
and shipped 150 tons of kaolin for the manufacture of fire brick. The 
kaolin was found to be satisfactory' for this purpose, but on account of 
the isolation of the property, expensive mining, and the irregular 
occurrence of the clay, it was not possible to compete with other sources 
of material. The kaolin was hauled 20 miles to Marysville, over a 
rough road, at a cost of $5 per ton for haulage alone. 

8ami)le No. 173 was taken for testing. The results are on i)age 313. 

Durst Ranch. One-half mile east of Wheatland. This locality was 
not visited, but a note on the occurrence of clay on this property was 
given in earlier reports as follows: "Shipments of clay were occa- 
sionally made, before 1905 ... to Gladding, McBean and Company 
at Lincoln. . . . The black clay loam used was 6 feet deep and over- 
lain by 18 inches of soil. Deposits similar to that on the Durst Ranch 
are abundant in the valley portion of Yuba County."^ 

Marysville Brick Company. This plant is a short distance north of 
Marysville, on the Feather River. A local surface clay is used for the 
manufacture of common brick. The plant was not visited and no 
details are available for publication. The production in 1925 was 
1,100,000 brick.2 

1 state MineraloRist's Rept. XV, p. 424, 1915-16, evidently abstracted from Bull. 
38, p. 230, 1906. 

= Clay-Worker, February, 1926, p. 139. 



CLAY RESOURCES AND CERAMIC INDUSTRY 237 



Chapter IV. 

CLAY TESTS AND THEIR INTERPRETATION AND THE 
CLASSIFICATION OF CLAYS. 

FIELD TESTS. 

While uo field tests of clays were made in preparing this report, tiie 
prospector or clay miner often wishes to deternune the possible eco- 
nomic value of clays before incurring the labor or expense of securing 
adequate samples and sending them to clay ])]ants oi' commercial labora- 
tories for testing. If samjjles are sent to clay plants it is usually neces- 
sary to send material to more than one plant, as a clay may be rejected 
by one operator as not being suitable for his ware or his plant routine, 
but this same clay may be eminenth' suitable in some other plant. 

The following sim[)le field tests for making a rough preliminary 
classification of clays, from the Third Report of the West Virginia 
Geological Survey, have been quoted many times, but are of such gen- 
eral interest to ])rospectors and others who are searching for clays in 
the field, that they are repeated here. 

1. A small lump of clay may be roasted in the flame of a gas stove. 
If it turns red or brown, the percentage of iron is high, probably more 
than four per cent. 

2. By tasting the clay, bitter salts, such as alum and epsom, may be 
detected, or such salts may occur a& white coatings on the outcrops 
of the clay in the bank. These salts are apt to form white wash coats 
on the finished brick, injuring their appearance. Sand may be detected 
by grit against the teeth. A rough idea of the percentage of such sand 
may thus be made. 

3. A good idea of its plastic qualities may be obtained by working 
the moist clay with the fingers. A good test for pottery clay is to 
thus moisten it, and determine whether it can be worked into a definite 
shape, and whether or not it will retain its form when dry without 
cracking. 

4. Shrinkage : A rough brick can easily be made and dried, and a 
good idea of the shrinkage arrived at. If it cracks or crumbles when 
dry or shrinks out of shape, its value is very doubtful. For this test, 
however, the clay should be ground thoroughly, tempered with water, 
and dried slowly. 

5. If carbonates of lime are present, a few drops of hydrochloric 
acid will cause effervescence or bubbling, as the carbonic acid gas 
passes off. Very high percentages of lime are apt to ruin the clay. 
Good fire bricks are made of clay low in lime content. 

6. The slaking of clays, or the crumbling down in tempering is tested 
by dropping a lump of clay in a cup of water. Some clays slake in a 
very few minutes, and so are easily tempered. 

7. The color of a finished clay product is largely determined by the 
amount of iron present. It is not always possible to predict the color 
of the burned ware from the color of the clay. It is true that red clays 
will usually burn red, but blue clays or those of other shades also com- 
monly burn red or buff. The color of the raw clay is often due to 
organic matter which is combustible, and will be consumed in the 
burninor. 



238 DIVISION OF MINES AND MINING 

While the above tests may not prove absolutely the quality of any 
fjiven elay, at the same time they furnish considerable valuable infor- 
mation in i-e^rard to it, and may be used to advantage by the owner of 
a deposit which has never been developed. If these simple tests seem 
to give ))ositive results it may then be well worth while to get in touch 
with buyers and consumers. 

LABORATORY TESTS. 

The methods of testing used for this report followed the standards 
or tentative standards of the American Ceramic Society,^ in so far 
as it was i)Ossible to do so with the ecpiipment and funds available. 

These methods or their equivalent have been followed in a number 
of recent state reports on clays.- Only such explanation of the testing 
methods and their inter])retation is given here as is necessary to an 
understanding of the text of this rei)ort and to indicate the divergences 
from the recommended methods. The reader is referred to the litera- 
ture for further details. 

Preparation of Samples. 

The weight of the sample collected in the field was usually a]i]iroxi- 
mately fifty pounds, but a number of them were smaller, owing to 
s]:)ecial difficulties of secnring proper samples or of transporting them. 
In sampling, the usual precautions were taken to secure material that 
was representative of the clay tluit would actually be mined. Notes on 
the macroscoi)ic character of the material sampled were made at the 
time of sampling, and are recorded in the description of the sam]ile. if 
of special interest. All foreign matter that normally would not be 
mixed with the elay, or that would be removed by screening before the 
clay is used in a elay-AAorking plant, was removed from the sample 
before shipment to the laboratory. 

In the laboratory, the entire sample was crushed to pass a 20-mesh 
screen, by passing through a laboratory jaw-crusher, followed by pass- 
ing through a set of rolls. One samjile, a flint fireclay (samjile Xo. 
282), was further crushed in a pebble mill to develo}) maximum 
plasticity. 

Sufficient water was added to the ground clay to permit the mixture 
to be Avorked into a plastic condition. The attemi)t was made to main- 
tain a uniform consistency, so that all determinations of water of 
plasticity and drying shrinkage would be comparable, but with a series 
of clays of widely-varying plastic properties, it is impossible to attain 
a high degree of uniformity in the ])lastic state, without the use of 
more elaborate methods than the scope of the investigation warranted. 

After thoroughly working (wedging) the plastic mass, it was covered 

• Report of the Committee on Standards. American Ceramic Society, Reprint from 
Yearbook, 1921-22, Ohio State fniversity, Columbus, Ohio. Price fifty cents. 

- Wilson, Hewitt, The Clays and Shales of Washington, Their Technology and Uses, 
Bull. No. 18. University of "Washington, Engineering Experiment Station, Seattle, 
Washington, October, 1923. 

Skeels, F. H., and Wilson. Hewitt, Preliminary Report on the Clays of Idaho. Bull. 
No. 2, Department of Mines and Geology, Idaho, 1920. 

Parmelee, C. W., and Schroyer, C. R. Further Investigations of Illinois Fire Clays, 
Bull. No. 38, pp. 273-417. Illinois Geological Survey, 1922. 

Reis, H., The Clays of Kentucky, Ky. Geol. Surv. Series VI. Vol. 8, Frankfort, Ky., 
1921. 



CLAY RESOURCES AND CERA^FTC TXDT'STRY 239 

with wot sacking and seasoned foi- at least 24 hoiii-s before test pieces 
were i)repared. 

Test Pieces. 

The test pieces were shaped in l)rass molds, 1} in. by 1 J in. by 8 in., 
inside dimensions. Full lenoth bars were nsed for dry transverse- 
strength tests, and test i)ieees for drying and firing data were made by 
cutting the bars into four pieces. A minimum of four 8-in. bars and 
sixteen 2-in. test pieces were made for all important clays of which 
there was a sufficiently large sample. The i)lastic weight and volume 
of three test i)ieces were determined as soon as they were molded. All 
volume measurements were made in a Goodner mercury volumeter.^ 

Drying. 

The test pieces and bars Avere thoroughly air dried in the laboratory, 
then heated in an automatic electric oven for five hours at a tem])erature 
between 64= C. and 7G C. and finally at 105 to 110° C. for at least 
12 hours. They were then transferred to a desiccator, where they 
remained until needed for dry weight and volume measurements, and 
for the dry transvei-se-strength test. 

Plastic and Drying Properties. 

Phisticihj : Notes on i)lasticity and molding properties were made at 
the time the test bars were molded. There is no satisfactory standard 
test or even a standard nomenclature to describe the plasticity of a 
clay in unambiguous terms. The term 'good ])lasticity' means a differ- 
ent condition to the common brick worker than it does to a stoneware 
worker. In general, the plasticity terms used in this report bear some 
i-elation to the ty]iical uses of the clay in question. The words 'short,' 
'weak,' 'crumbly,' 'smooth,' and 'sticky' are used wherever they serve 
to clarify the meaning of tiie more general words 'poor,' 'fair,' 'good,' 
and 'excellent.' 

Some shales and indurated clays can be rendered more ])lastic by 
fine grinding.- The test data on such clays are of little value without 
l)articular reference to the preliminary preparation of the sample. 

Water of Phisficifii: The water of i)lasticity is tlie amount of water 
required to render a clay readily workable. It is calculated as a per- 
centage of the Aveight of the dry clay bar, according to the following 
formula : 

plastic wcifjht — dry weight 

Per cent water of plasticity = X 100 (1 I 

dry weisiit 

Shrinkage Waier: The water that is removed from a clay while it is 
shrinking from the pla.stic to the dry state is called the shrinkage water. 
It is calculated as follows: 

Plastic volume — dry volume 

Per cent shrinkage water = X 100 (2) 

dry weight 



' Goodner, E. F., A Mercury Volumeter, Jour. Am. Cer. Soc. Vol. 4, p. 228, 1921. 
- Walker. T. C. The Effect of Fine Grinding on an Industrial Clay. Jour. Am. Cer. 
Soc, Vol. 10, p. 449, June. 1927. (A Southern California clay was used in this study.) 
See also the results on sample No. 2S2, this report, page 2S2. 



240 DIVT^'O"' •" Ay "MINING 

Pore Wafer: Pore "vvater is that jiortion of tlie water of plasticity 
that is retained in the pores after shrinkage ceases. It is calculated as 
follows : 

Per fiMit iM)i(' w.iter ^ per cent water ol' plasticity — per cent shriukage water (8) 

Clays in which the percentage of shrinkage water is high may have 
excessive or sticky plasticity, and usually must be carefully dried to 
prevent warping or cracking. According to A. V. Bleininger/ the 
ratio of pore to shrinkage water shoidd not exceed 1.00 for bond clays, 
nor 0.75 for strong heavy plastic clays. 

Shrinkage : Drying shrinkage is most accurately determined by 
determining the volume shrinkage, then calculating the linear from the 
volume shrinkage. Volume shrinkage is calculated as follows, in per- 
centage of dry volume. 

plastic volume — dry volume 

Per cent dry volume shrinkage = X 100 (4) 

dry volume 

The linear drying shrinkage, in per cent of drj^ length, is calculated 
as follows: 

Calculated linear diying shrinkage = 



[,3/ drv volume shriukage f 

V 1 + . — 1 X lOU (5) 

100 J 

In addition to calculated values of linear drying shrinkage, direct 
measurements were made by means of shrinkage marks on the 8-in. 
bars. These measurements are not reported, as they are inaccurate, 
and serve only as an approximate check on the calculated values. 

For many purposes, the drying shrinkage is expressed in per cent 
plastic volume or length. Either of these may be calculated from the 
data given in this rei)ort by means of the following formulas: 



Volume drying shrinkage, per cent plastic volume = 

volume drying shrinkage, per cent dry volume 

100 + volume drying shrinkage, per cent dry volume 

Linear drying shrinkage, per cent plastic length = 

linear drying shrinkage, per cent dry length 

100 + linear di\ving shrinkage, per cent dry length 
Linear drying shrinkage, per cent plastic length = 



X 100 (G) 



X 100 (7) 



- f/i 



vol. dry. shrink., % plastic vol. 
100 



X 100 (8) 



For convenience in making the large number of calculations for this 
report, tables of values were prepared for equations (5) and (8). As 
■will be noted later, equation (8) is the proper form to use for the 
calculation of linear firing shrinkage, in per cent of dry volume. 

Dry Transverse Strength : The dry modulus of rupture was deter- 
mined on practically all of the clays tested. The 8-in. dried test bars 

' Bleininger, A. V., Properties of American Bond Clays, etc., U. S. Bur. of Stand- 
ards, Tec. Paper No. 144, p. 51, 1920. 



CLAY RESOURCES AND CERAMIC INDUSTRY 241 

"were of such a lenjjtli that one jl-in. Iji-cak and two ■^-'n\. breaks could 
be obtained on each bar. Tlie bars rested on ^-in. rollers, and the pull 
stirruj) also was efiuipped with a roller-bearing^ surface, so that the 
daufier of shear breaks was niinimized. Xo difference was noted in the 
average values obtained on the o-in. and the 8-in. breaks. At least ten 
breaks were made on all clays of which sufficient material was available 
for making the requisite number of test bars. A variation of plus or 
minus 15% from the average modulus of rupture was allowed, and 
at lea.st eight out of ten breaks came within these limits, unless noted 
in the text by tlie approxinuition symbol (zh). Where necessary, the 
tests were repeated until a set of consistent i-esults was obtained. 
The modulus of rupture is calculated by the following formula : 

Modulu.s of rupture, lb. per sq. in = 

3 X breaking load in pounds X distance between supports in inches 

(9) 

2 X breadth in inches X (deptii in inches )-' 

On the stroiiger clays, especially on the 3-in. breaks, it was necessary 
to use a lever Avith a ratio of 2.86. The lever ratio is multiplied by the 
breaking load to determine the breaking load at the point of application 
for use in equation (9). 

A nomogra{)]i was used to minimize tlie calculations involved. 

The following classification of clays by modulus of rupture is used in 
the text of this report : 

Metlium Medium 

Low low Medium hiffh High 

Modulus, lb. per sq. in to 100 100 to 200 200 to 400 400 to SOO above 800 

This is the same classification as that suggested by "Watts ^ for bond- 
ing strength (q. v. below) and is an elaboration of that used by Parme- 
lee and Schroyer.- 

Bonding Strength: The modulus of rupture of dried bars containing 
equal parts of clay and standard Ottawa sand ■' is known as the bonding 
strength. It is of importance in all clays that are to be used with non- 
l)lastic material. A few bonding strength determinations w^ere made 
for this report. See samples No. 83, 273 and 280, pages 297, 273 and 
305. It was intended to include more of tliese determinations, but it 
was found that to do so would unnecessarily delay the publication of 
this report. For an especially interesting comparison between dry 
modulus of rupture and 'bonding strength,' the reader is referred to 
the test results of Parmelee and Schroyer.* It will be noted that in 
some cases the bonding strength is higher than the dry modulus, but 
that in general the addition of 50% of sand to a clay lowers the trans- 
verse strength by 30% to 60%) of its original value. 

Fineness: The percentage of non-plastic material remaining on a 
200-mesh (0.0029 in. ajierture) screen was determined for most of the 
clays tested. Fifty grams of the clay was taken, broken in a mortar 
and passed through a 10-mesh screen. The sample was placed in an 

1 Watts, A. S., Classification of Clays on a Ceramic Basis. Jour. Am. Cer. Soc, 
Vol. 3, p. 247, 1920. 

2 Parmelee, C. W., and Schroyer, C. R., op cit.. p. 293. 

^Standard sand is sized between the limits of minus 20-mesh (0.0328 in. aperture) 
'•nd plus 2S-mesh (0.02."i2 in. aperture). It i.s used in the testing of cement. 
* Op. cit. 

16 — 54979 



242 



DIVISION OP MINES AND MINING 



Erlenmever flask -with 150 ce. of distilled -water and 1 cc. of ammonia. 
The i)ul]) was thoi-ouglily shaken, let stand for 18 liours, and agitated 
for 10 minutes in a shalving machine such as that commonly used in the 
phosphorus determination in steel. The pulp was transferred to a 
200-mesli screen, and all nndersize was -vvashod through the screen with 
a fine jet. The oversize was dried and weighed, and the result reported 
in per cent of plus 200-mesh material. 

Firing Properties. 

Firing Treatment : A test piece of each clay was fired to each alter- 
nate cone number from cone 010 to cone 13, except where insufficient 




Photo No. G7. 



Assay laboratory, Stanford University, showing nuitfle furnaces 
in which test pieces were lired. 



material was available to make enough test pieces for the complete 
series. In addition, most of the refractory clays were fired to cone 15. 
Denver Fire Cla.y Company oil-fired assay muffle furnaces were used 
for all firing from cone 010 to cone 13. These furnaces, shown on 
photo No. 67, were very satisfactory for the purpose, as the tempera- 
tures could be readily controlled, and since ten furnaces w^ere available, 
it was possible to place one or two sets of 30 samples in each muffle. 
If two sets of test pieces were placed in the same muffle, the set in the 
rear of the muffle was fired to two cones higher temperature than the 
set in the front, and the two sets were separated from each other by a 
full sized fire brick. This method of firing eliminated most of the trans- 
ferring of test pieces to a cooling furnace that is a disagreeable and 



CLAY RESOURCES AND CERAMIC INDUSTRY 



243 



unsatisfactory feature of most test Avork of this kind. The bottom 
tiers of test pieces were kept from contact with the muffle floor by 
placinj; tliom on .small fircchiv' saddh^s. Tlie fiiniaec tliat was used for 
firing to cones 11 and 1:5 was ('(juipped with a Carbofrax muffle, and 
with Carbofrax stools and muffle i)rotector plates. It was difficult to 
fire to these temperatures without flashing the test pieces. 

A Fisk ^ pre-mix ga.s-fired kiln was u.sed for firing to cone 15. This 
furnace, shoAvn on photo No. 68, has a 12-in. circular firing chamber, 




Photo No. 68. Fisk pre-mix gas-fired labora- 
tory kiln, in ceramic laboratory, Stanford 
University. This is used as a load and 
spall furnace and for firing tests to a 
maximum temperature of cone 30 (1650° 
C). All cone 15 tests were fired in this 
kiln. 

and is capable of accurate temperature control and good heat distribu- 
tion. The same furnace is used for load and spall tests of refractories, 
and is suitable for test work up to cone 30 (1650° C). 

Pyrometric Control: Temperatures were controlled with the aid of 
base-metal or preciou.s-metal thermocouples, in addition to Orton stand- 
ard pyrometric cones alongside the test pieces. The firing schedule 

' Fisk, H. G., A Practical Gas-Fired Test Furnace for Plant Use. Jour. Am. Cer. 
Soc, Vol. 9, p. 151, March, 1926. 



244 



DIVISION OF MINES AND MINING 



was at a rate 50 '^f faster than the fastest schedule recommended by 
the American CVramic Society, aA'era<rinfr ajiproximately 90° C per 
hour, but at a shiwer rate during the Avater-smoking period, a faster 
rate between the ranp:e of 600° C. and 100° C. below the desired finish- 
ing temperature, and a slower rate again at the finish. While this 
schedule caused more shattering and splitting of some of the test pieces 
than would have been the case if a slower schedule had been followed, 
the data on shrinkage and porosity at various firing temperatures are 
comparable with each other, and can be correlated with the results that 
liave Ix'cn reported by other investigators/ Tn the final analysis, no 
laboratory tests of clays can be interpreted in a strict quantitative 
sense with the results obtained in commercial practice, and the purjiose 
of the small-scale tests is to tentatively classify a given clay according 
to its commercial uses with the minimum expenditure of time and 
money. The final decision as to tlie utility of a clay and the methods 
of working it to obtain the best results, must always be determined in 
a commercial plant, where the shaping, drying and firing can be done 
on full-sized ware. 

For convenience of reference, the end points of Orton cones are 
given in degrees Centigrade and Fahrenheit, in table No. 9. 



TABLE No. 9. 
End Points of Orton Pyrometric Cones, in Centigrade and Fahrenheit Degrees 

(Heated in Air). 

(From Fail-child, C. O., and Peters, M. F., Characteristics of Pyrometric Cones, 
Jour. Amer. Cer. Soc, Vol. 9, p. 738, 1926.) 





• 


End point 










End point 








Heated 


Heated 




Heated 


Heated 


Cone 


at 20 


' C./hr. 


at 150° 


C./hr. 


Cone 


at 20" 


C./hr. 


at 150° 


C./hr. 


No. 


".C. 


"F. 


° C. 


°F. 


No. 


"C. 


"F. 


° C. 


° F. 


022 


585 


1085 


605 


1121 


11 


1285 


2345 


1325 


2417 


021 


595 


1103 


615 


1139 


12 


1310 


2390 


1335 


2435 


020 


625 


1157 


650 


1202 


13 


1350 


2462 


1350 


2462 


019 


630 


1166 


660 


1220 


14 


1390 


2534 


1400 


2552 


018 


670 


1238 


720 


1328 


15 


1410 


2570 


1435 


2615 


017 


720 


1328 


770 


1418 


16 


1450 


2642 


1465 


2669 


016 


735 


1355 


795 


1463 


17 


1465 


2669 


1475 


2687 


015 


770 


1418 


805 


1481 


18 


1485 


2705 


1490 


2714 


014 


795 


1463 


830 


1526 


19 


1515 


2759 


1520 


2768 


013 


825 


1517 


860 


1580 


20 


1520 


2768 


1530 


2786 


012 


840 


1544 


875 


1607 












Oil 


875. 


1607 


905 


1661 


23 


In Arsem 


1580 


2876 












26 


furnace at 


1595 


2903 


010 


890 


1634 


895 


1643 


27 


600»C.(: 


= 1080°F.) 


1605 


2921 


09 


930 


1706 


930 


1706 


28 


per hr 


. 


1615 


2939 


08 


945 


1733 


950 


1742 


29 






1640 


2984 


07 


975 


1787 


990 


1814 


30 






1650 


3002 


06 


1005 


1841 


1015 


1859 












05 


1030 


1886 


1040 


1904 


31 






1680 


3056 


04 


1050 


1922 


1060 


1940 


32 






1700 


3092 


03 


1080 


1976 


1115 


2039 


33 






1745 


3173 


02 


1095 


2003 


1125 


2057 


34 


1755 


3191 


1760 


3200 


01 


1110 


2030 


1145 


2093 


35 


1775 


3227 


17 85 


3245 












36 


1810 


3290 


1810 


3290 


1 


1125 


2057 


1160 


2120 


37 


1830 


3326 


1820 


3308 


2 


1135 


2075 


1165 


2129 


38 


1850 


3362 


1835 


3335 


3 


1145 


2093 


1170 


2138 


39 


1865 


3389 






4 


1165 


2129 


1190 


2174 


40 


1885 


3425 






5 


1180 


2156 


1205 


2201 












6 


1190 


2174 


1230 


2246 


41 


1970 


3578 






7 


1210 


2210 


1250 


2282 


42 


2015 


3659 






8 


1225 


2237 


1260 


2300 












9' 


1250 


2282 


1285 


2245 












10 


1260 


2300 


1305 


2381 













' See In this connection : Brown, G. H., and Murray, O. A., The Function of Time 
in the Vitrification of Clays, Trans. Am. Cer. Soc, Vol. XV, p. 193, 1913. 



CLAY RESOURCES AND CERAMIC INDUSTRY 245 

Firing Shrinkage: The shrinkage resulting from firing may be 
expressed as the per cent volume or linear shrinkage, in terms of plastic 
or tlry volume or lengtli. The data in this report are given in terms of 
volume and linear shrinkage, dry basis, and in the written summaries of 
each clay, the maximum total linear shrinkage, plastic basis, is given. 
The equations for calculating these various methods of expressing fired 
shrinkage from the volume determinations are as follows: 



^'ohime firiiif; sliriiikage. per ot'iit dry volume = 

dry volume — fired volume 



dry volume 
Linear firing shrinkage, per cent dry length = 



X 100 (10) 



yV volume firing shrinkage. % dry volume 



I vV volume nring snrinKage. Vr (iry volume 
1 — V 1 X too (11) 

L 100 J 

(See equation S) 

Total linear shrinUagt'. per cent plastic length = 
(lin. dry shrink., % dry length + lin. firing shrink. % dry length) 



100 + lin. dry shrink., '/c dry length 



X 100 (12) 



All fired volume measurements were made in the mercury volumeter 
after saturating the test pieces with water^ and weighing them for the 
absorption and apparent porosity calculations. In this way, the volume 
measurements ap])roximate the bulk, or outside, volume of the test 
pieces, as the mercury does not readily enter the small pores and dis- 
place water, during the short time of contact in the volumeter. How- 
ever, some mercury undoubtedly enters the larger of the open pores 
(excluding from consideration all vugs, cavities and drying or firing 
cracks), hence the calculations of volume and linear firing shrinkage, 
as well as those of absorption, apparent porosity, apparent specific 
gravity, and apparent density, are slightly erroneous. 

Absorption: The absorption of fired test pieces was determined 
by noting the weight of water absorbed by boiling the piece in distilled 
water for two hours. 



I'er cent absorption = 



saturated weight — dry fired weight"! 



X 100 (13) 



dry firwl weight J 

Apparent Porosity: Apparent porosity is the ratio between the volume 
of the unsealed pores and the volume of the whole piece (=bulk vol- 
ume). It is calculated from the following equation: 

saturated weight — dry fired weightl 

1 X 100 (14) 



Per cent apparent porosity 



fired volume 



Apparent Specific Gravity: Apparent specific gravity or bulk 
specific gravity is the relation between the weight of a mass of 
material as a whole and that of a volume of water equal to the volume 
of the solid material plus the sealed i)ores^. No values of apparent 

' The pieces were boiled in distilled water for at least two hours, tlien allowed to 
cool in tlie water. Before weighing, the surplus water was removed from the surface 
of the test pieces witli a damp cloth. 

- Searle, A. B., The Chemistrv and Phvsics of Clays and other Ceramic Materials, 
p. 203. 



246 DIVISION OF MINES AND MINING 

specific gravity are given in this report, but they may be calculated 
for the fired test pieces from the absorption and apparent density, if 
these are not zero, according to the following equation : 

Apparent specific gravity = 

per cent apparent porosity X 100 

(15) 

percent absorption X (100 — percent app. porosity) 

Apparent Density: Apparent density or bulk density is the relation 
between the weight and volume of an article or material as a w^hole 
(including any pores or voids) and that of the weight of an equal 
volume of waters Values of apparent density are not given in this 
report, but if the absorption and apparent porosity are not zero, the 
apparent density can be calculated as follows: 

per c-ent apparent porosity 

Apparent density = (16) 

per cent absorption 

True Specific Gravity: True specific gravity is the relation between 
the Aveight of a substance and the true volume of the grains of wdiich 
the material is composed. On porous materials, which may contain 
sealed pores, the sample must first be ground to a fine powder to 
remove all pores.. The true specific gravity of the powder is then 
determined by means of a specific gravity bottle or pyenometer. No 
such determinations were made for this report, nor can they be 
calculated from the data available. In many cases, the apparent 
specific gravity closely approximates the true specific gravity. 

Softening Point. 

The softening point of a clay or ceramic mixture is defined as that 
temperature (usually expressed in cone numbers) at which a standard 
tetrahedron of the clay when mounted and heated in a manner here- 
after described, will bend until it touches the base upon which it 
stands. The standard tetrahedron is the same size and shape as the 
small Orton standard pyrometric cones, 7 mm. along the edge of the 
base and oO mm. high. The word 'cone' is in general use to describe 
these tetrahedra. The test cones are mounted on a plaque of refrac- 
tory material, and are embedded not more than 2 mm. in the plaque, 
at an angle of 75° from the horizontal. 

The terms 'fusion point' or 'deformation point' are often used 
interchangeably with 'softening point.' 'Fusion point' should be used 
to indicate the temperature at which complete loss of the original shape 
occurs, and 'deformation point' is best applied to the temperature at 
which alteration of the original shape begius. 

The softening-point determinations recorded in this report were 
made in an oxy-aeetylene furnace, after a design by Hewitt Wilson.^ 
An illustration of the furnace is given in photo No. 69. 

Six cones were placed on each plaque, which were usually made 
from alundum cement. The cones were arranged in tAvo rows of three 
each, back to back, and were spaced as close together as possible. The 

' Searle, op. cit. 

= Wilson, Hewitt. An Oxvgen-Acetylone High-Temperature Furnace. Jour. Am. 
Cer. Soc, Vol. 4, p. 835, 1921. 



CLAY RESOURCES AND CERAMIC INDUSTRY 



247 



four cones at the corners were Orton standard cones, and tlie two 
middle cones were of the clay to be tested. Preliminaries were first 
run, with four different standard cones in the corners, and usually 
with (litferent unknown cones in tlu' middh' positions. A tinal check was 
always made with two cdiics of the same clay in tlic middh' ])Ositions, 
a jiair of stanchird cones ol' one number on one side, and a pair of 
staiulard cones of the nc.xl lusher (or lowei-) numbci- on the other side 
of the plaque. 

After the tiii-nace was heated to the desii'cd temperature, each 
fusion normally rciiuii'cd I'loiii llircc to six minutes. All cones of 
clays tested for this I'cpcn-t were biscuitcd at ISOO F. Ix'fore setting 




Photo No. tii). Wilson oxy-acetylene c-one fusion furnace in ceramic laboratory, 
Stanford University. (After design of Prof. Hewitt Wilson.) 



in plaques for the softening-point determination. If this is done, 
and if the ])laques are dried, and pre-heated by placing on top of the 
furnace, they may be introduced into the hot furnace without danger 
of s]>alling. 

Tlie results are reported to the nearest half-cone number, using the 
notation A-li {cj/., 31-;}2) to signify tliat tlu; softening i)oint lies 
nearer to A^ than to either A or B. Closer estimation, such as A — , 
A -|-, B — , or B -I-, was not considered to be justified by the limits of 
accuracy of the method itself, and leads to indefiniteness in that such 
notations might be read to signify 'less than' or 'greater than,' without 
setting the maximum or minimum range of the values as reported. 



248 DIVISION OP MINES AND MINING 

For the purposes of tliis bulletin, all clays havinjj^ a softening point 
of cone 27 or higlier are classified as refractory, and those which fuse 
at cone 33 or above are considered to be highly refractory.^ 

Texture, Structure, and Hardness. 

Texture: Tlie texture of dried and fired test pieces is reported as 
fine-, medium-, or coarse-grained, depending upon the average size 
of the grains in the mass, and as close- or open-textured, depending 
upon the grading of the grains. This classification is nsed in order to 
permit a distinction betAveen those clays that may contain a large 
proportion of non-plastic grains that approximate uniform size, and 
those that contain clay and graded non-pla.stic grains in .such propor- 
tions as to give a closely knit, dense texture. 

Structure: The structure of fired test ])ieces is rei)ortefl as granular, 
stony, homogenous (with textural (|ualifications), or heterogeneous 
(with textural qnalifications). The soundness of a fired test piece is 
indicated by such terms as sound, hair-cracked (the development of 
Avhat many ceramic Avorkers term 'crow-feet'), shattered, or as cnn- 
taining one or more .small or large cracks. 

Hardness: The hardness of the fired test pieces is reported as greater 
or less than finger-nail (== 2| in ]\Ioh's scale) or steel (= 5i in 
Moh's scale). The hardness of dried clays is reported as very soft, soft, 
medium, equal to the finger-nail, or greater than the finger-nail. 

Color. 

The natural and fired colors of clays and ceramic products are too 
often expressed in indefinite terms that can not be duplicated by other 
investigators. Since the fired color of a clay or clay mixture is one of 
its mo.st important properties, some standard scale of colors should be 
used. For that reason, more attention is ])ai(l in this work to an accurate 
designation of color than is customary in similar publications. AVhile 
the colors obtained under laboratory firing conditions are not exactly 
the same for each firing temjierature as Avould be obtained in commer- 
cial kilns, the color possibilities of a given clay are clearly indicated 
by the laboratory tests. 

The two princi])al standard color scales in use in the TTnited States 
ai'e the Ridgway- and the ^lunsell'' systems.* For reasons hereafter 
noted, the Ridgway system is used in this bulletin. Since this is, so far 
as is known, the first time that either system has been used in a bulle- 
tin of this nature, a brief explanation of color terms and of each of the 
systems is given, together with an approximate correlation of parts of 
the two systems with each other. 

To adequately express a color, three variables must be used :^ (1) 
Hue, or the series of spectrum colors and their intermediates, through 



' Parmelee, C. W., and Schroyer, C. R., op. cit., p. 281. 

= "Color Standards and Color Nomenclature." by Robert Ridgway. I'ublished by A. 
Hoen and Company, Baltimore, Maryland, l!n2. Price $12. 

■■"'A Color Notation." bv A. H. Munsell, Tth edition. 1920 (price $2), and "Atlas of 
the Mun.sell System," 1915 (price $25), both published l)y the Munsell Color Company, 
Baltinioi'e, Maryland. 

■• Lenchner. Theodor, "A Study of Color and Its Appplication to Ceramic Art." 
Jour. Amer. Cer. Soc, Vol. 10, p. 538, July, 1927. in which a combination of the 
Munsell and the Prang (an earlier work) systems is proposed. 

^ In preparing this paragraph, Munsell's "A Color Notation" was freely drawn upon. 



CLAY RESOURCES AND ( EKAMIC INDUSTRY 240 

red. ormifre, yellow, jrreen, Miic and violet. Hue can be accurately 
expres.sed by detenniiiiiijr tlie wave jenji'th of tbe lip-bt waves of each 
color sensation. (2) Tone or value, by which a lijrlit color is distiu- 
g-uished from a dark one. When white is added to a color, various tints 
result, and when black is added, the shades are in-oduced. Tone can be 
measured by nutans of a photometer, and is ex])ressed scientifically in 
terms of the amplitude of the light waves reflected by the color. (8) 
Chroma, by whieh stronjr colors are distinguished from weak ones. 
It is the effect ])roduced by addingf neutral g:ray to a hue of any given 
tone. Scientifically, it is the purity of one wave leng-th sei)arated from 
all others. 

Ridgwafi Color S^tanfhird.'i: The key to the Ridgway classification 
consists of 36 hues, which include the six fundamental spectrum colors, 
red, orange, yellow, grreen, blue, and violet, which are connected by 
intermediate hues. The chromatic scale forms the horizontal line of the 
entire series of charts. The vertical scale on all charts, except the 
carbon-gray series, represents the tone (Munsell's "value") or lumi- 
nosity. That is, the proportion of black or white which is mixed with 
the full color. 

The first series of Ridgway's plates contains the pure colors. This 
.series is repeated five times with successively increasing amounts of 
neutral gray, but with some hues omitted in the last three series. These 
series are designated "broken color scales" by Ridgw^ay, but Munsell's 
term "chroma" is to be ])referred. 

The complete designation of a color from Ridgway's charts therefore 
involves the use of three symbols: (1) an arable numeral to designate 
the hue; (2) the superscript (' to ' ' ' ' ') to indicate the chroma; and 
(3) a loAver-case letter to designate the tone (or value). Thus, o'k 
is a hue containing 60'';/ red and 40% orange, shaded with 70.5% 
of black, and the Avhole mixed with 32% of neutral gray. The result 
is a brick red. It is possible to interpolate between the Ridgway colors 
whenever an exact match can not be found, and the.se can be designated 
by the alternate symbols that are omitted from the color charts. No 
attempt was made to exi)ress the clay colors in this bulletin closer 
than the nearest Ridgway number. 

Expressed in common color names, the Ridgway hues 1, 3, 5 and 7 
either of tone "b" or unaltered as to tone, are "red"; 9, 11, 13 and 15 
of the same tones are "orange"; and 17, 19, 21 and 23 of the .same 
tones are "yellow." Colors that would be classed as "pale" or "verv 
light" are of tone "f." "Pink," "light orange," "light yellow," 
"huff," etc., are tone "d." The "i" tones, as well as the "k" tones 
in hues 1, 3 and 5, are those that would be designated as "dark." The 
"k" tones, except in hues 1, 3 and 5, are "browns"; for example, "red- 
brown. " ' The " m " tones are ' ' dark-browns. ' ' With respect to chroma, 
the pure spectrum series is purer than will be foimd in most ceramic 
products, although many glazes fall into this class. The (') series 
includes most glazes, especially matt glazes, as well as the more bril- 
liantly colored red- and pink-burning bodies. The (") series includes 
the greater poi-tion of all pink-, buff-, and red-burned clay products. 
The ('") series includes colors that are generally too dull for artistic 
purposes. The ("") and the ('"") series are decided grays, of little 
interest in decorative wares. 



250 DIVISION OF MINES AND MINING 

Munsell Color Stancla)-ch: The Munsell system uses the conception 
of a sphere to evaluate the tliree eoh)r constants. Each of the con- 
stants is theoretically divided into ten equal parts. Hue is the hori- 
zontal scale around the circumference of the sphere, and is designated 
by an upper-case letter represent ing an abbreviation of the color, as 
red (R), yellow-red (YR), Yellow (Y), etc. These letters are pre- 
ceded by a numeral from 1 to 9 to represent the position of the color in 
the scale of hues. For exami)le, ".IR" is the ''middle hue" of red. 
These symbols are followed by a fraction, the numerator of which 
designates the value and the denominator of which designates the 
chroma. "Value" is represented as the vertical axis of the color sphere, 
with white (value 10) at the top and black (value 0) at the bottom, 
but samples are shown only for values 2 to 9, inclusive. "Chroma" is 
traced by radii at right angles to the vertical axis of the spliere. An 
approximation of Ridgway's 5'k is given in the Munsell system as 
7R 3/7 but the nearest color actually shown on the charts is 5R 3/7, 
which lies between Ridgway's I'k and I'm. 

Ridgway vs. Munsell: The Ridgway system was chosen for this work 
in preference to the Munsell system for the following rea.sons: (1) 
Ridgway's s.ystera includes 1115 named and systematized colors, 
whereas the Munsell Atlas contains but 340 different colors, which, 
liowever, are completely duplicated in two different arrangements, and 
})artly duplicated in two other arrangements. (2) The Ridgway 
system has 36 colors in the scale of hues, whereas the Munsell system 
presents but 10 different hues. Each system uses the same number of 
subdivisions in the scale of tone. While the Munsell system provides 
for a maximum of 10 divisions of chroma compared to 6 for the Ridgway 
charts, not all of these divisions are used on all tones and hues in either 
system and the average chroma scale has approximately the same 
number of divisions in each system. As noted by by Lenchner ^ the 
Munsell system would be greatly improved by the addition of more 
hues. (3) The Ridgway charts are bound in an octavo book, of 
a]>proximately one-third the bulk and weight of the IMunsell Atlas, yet 
each color has an area of 0.5 sq. in., compared to 0.4 sq. in., and the 
minimum space between each color sample is \ inch, compared to -^ 
inch on the Munsell charts. These are important factors influencing 
the efficiency of use of the two systems for the purpose of matching 
colors. The charts in either system may be removed from the book, 
and mounted side by side on a wall or table, preferably under glass. 
In this case, the Ridgeway charts occupy a minimum space of 10.3 
sq. ft., and the Munsell charts occupy 11.2 sq. ft. When so arranged, 
the Ridgway system still possesses a distinct advantage in the time 
required to match a color and record it accurately. (4) All of the 
Ridgway colors are named, as well as numbered. This is frequently 
of value in preparing written descriptions, and for other purposes. 
(5) The Ridgway system costs less than half as much as tlie Munsell 
system, and there is no difference in tlie life of the colors when exposed 
to light, lience replacements of RidgAvay's charts can be made more 
cheaply when the colors have faded. 

A tabulation of the Ridgway colors most frequently used in this 
report is given in Table No. 10, with an approximation of the corres- 

» Ov- cit. 



CLAY RESOURCES AND CERAMIC INDITSTRY 



251 



poiiilinji- Muiisell color. This comparison was made visually by three 
persons ' indei)endentl3% and average values are reported. This correla- 
tion makes no claim to scientific accuracy but a])iiroximates the result 
that would be obtained by the average user of either set of charts. 



TABLE No. 10. 
Visual Correlation of Certain Ridgway Colors with Munsell Colors. 

Approximate 
Uidgway Munsell 
.syml)ol equivalent 





Ai)prt)ximate 




Ai)i)ioximat 


Ridgwa> 


Munsell 


Ridgway 


Munsell 


symbol 


etiuiv 


ilent 


symbol 


equiv 


ilent 


5'i 


7R 


5/9 


3"d 


IR 


7/4 


k 


7R 


3/7 


b 


4R 


6/5 


m 


6R 


3/4 




3R 


5/7 


7'f 


7R 


8/4 


i 


5R 


4/5 


d 


8R 


7/6 


5"f 


3R 


7/3 


b 


8R 


6/8 


d 


5R 


7/4 




9R 


5/8 


b 


5R 


6/5 


1 


9R 


4/7 


_ 


5R 


5/7 


k 


9R 


4/6 


i 


7R 


4/5 


m 


7R 


3/4 


k 


7R 


3/4 


9'f 


8R 


8/4 


m 


7R 


3/3 


d 


9R 


7/5 


7" f 


6R 


8/3 


b 


lYR 


6/7 


d 


7R 


7/4 




lYR 


6/8 


b 


9R 


6/5 


~i 


2YR 


5/7 




9R 


5/7 


k 


lYR 


5/7 


i 


9R 


4/5 


m 


9R 


3/4 


k 


9R 


4/4 


ll'f 


9R 


8/4 


m 


8R 


3/4 


d 


SYR 


8/r, 


9"f 


6R 


8/4 


b 


SYR 


7/7 


d 


9R 


7>6 




SYR 


6/8 


b 


9R 


6/5 


1 


SYR 


5/7 




9R 


5/6 


k 


4YR 


4/5 


i 


1YR 


5/5 


m 


SYR 


3/5 


k 


lYR 


4/3 


13'f 


5YR 


8/5 


m 


lYR 


3/4 


d 


SYR 


8/5 


n"f 


7R 


8/3 


b 


SYR 


7/7 


d 


2YR 


7/5 


15'f 


4YR 


8/5 


b 


lYR 


6/6 


d 


6YR 


7/7 


_ 


lYR 


5/6 


1) 


7YR 


7/8 


i 


2YR 


5/6 


17'f 


7YR 


8/5 


lS"f 


9R 


8/3 


d 


7YR 


8/5 


d 


SYR 


8/5 


b 


ttYR 


7/8 


b 


SYR 


7/7 


19'f 


5Y 


8/6 


j 


SYR 
SYR 


6/6 
5/6 


l"f 


2R 


7/3 


ir,"f 


9R 


8/4 


d 


8RP 


7/4 


d 


4YR 


8/5 


b 


IR 


7/5 


b 


SYR 


6/6 




3R 


5/5 




4YR 


6/6 


3"f 


3R 


7/3 


i 


5YR 


5/5 



17"f 


2YR 8/4 


d 


GYR 8/4 


b 


7YR 7/7 


_ 


7YR 6/5 


i 


7YR 5/5 


19"f 


7YR 8/3 


d 


9YR 8/5 


b 


9YR 7/7 




9YR 6/7 


1 


9YR 5/6 


l"'f 


6RP 8/2 


d 


6RP 7/4 


b 


9RP 6/4 


5"'f 


9RP 8/2 


d 


9RP 7/3 


b 


3R 6/4 




3R 5/4 


i 


3R 4/4 


9"'f 


4R 8/2 


d 


4R 8/2 


b 


4R 6/4 




6R 5/4 


i 


8R 4/4 


k 


8R 3/4 


lS"'f 


5R 8/1 


d 


5R 8/2 


b 


7R 7/3 




lYR 5/4 


1 


2YR 4/4 


k 


3YR 4/3 


17"'f 


SYR 8/2 


fl 


SYR 7/3 


b 


4YR 6/3 




7YR 6/3 


i 


7YR 5/3 


k 


SYR 4/2 


L'l"'f 


4Y 8/2 


d 


6Y 8/3 



Color Classification of Clays: The clays desci'ibed in this report are 
classified as to color into four groups, following Parmelee and Schroyer," 
but definitely fixing the boundaries of each group by the use of Ridg- 
way 's colors. The classification is as follows: 

I. Clays Burning White or Cream Colored, not Calcareous. Into 
this group are placed all clays that fire at the highest firing tempera- 
tures used, to tones nearer to white than Ridgway 's "f " tones. There 
is need for an extension of standard color nomenclature into this range," 
but in lieu of a well-established system, the terms "yellowish- white," 
"pinkish-white," "grayish-white," etc., are used in this report. All 
of the clays in this group lire to colors that are sufficiently good to 
permit the use of the clay in stoneware bodies, most of them can be 
used to some extent in sanitary ware and electrical porcelain, if other 



1 Prof. F. G. Tickell, Stanford University, Mrs. Bernice L. Tickell, and the author. 

= Parmlee, C. W., and Sohroyer, C. R., "Further Investigations of Ulinoi.s Fire 
Clays," 111. Geol. Surv. Bull. No. 38, p. 278. 

' See in this connection : Lofton, R. E., A Measure of the Color Characteristics of 
WHiite Papers, U. S. Bur. Std. Tech. Paper 244, 192S. 



252 DIVISION OF MINES AND MINING 

properties are suitable, and a few are -\vliite enoii<i]i for nse, when 
washed free from sand, in phice of En<«:lish china clay. 

II. Buff-Burninp: Clays. Into this class are ])laced all clays that fire 
to tones corresponding to Ridgway's "f" tones, all "d" tones from 
hue 9 to 19, inclnsive, and all "b" tones from hue 15 to 19, inclusive. 
Exceptions are noted in group IV. 

III. Clays Burning Red, Brown, or Other Dark Colors. Into this 
group are placed all clays, excepting those of group IV, that fire to 
colors darker than those of group II. 

IV. Clays burning Dirty White, Cream White, or Yellowish White. 
The clays of this group are mainly calcareous or magnesian, and color 
is not an important criterion. 

Chemical Analysis. 

The relative value of chemical analyses in the study of clays has been 
well summarized by Hewitt AVilson^ as follows : 

"Chemical analysis provides its most effective usefulness, in the case of the high- 
grade clays, in estimating the degree of purity of the white-burning, kaolin-like 
materials and the alumina-silica-fiux ratio in the fire clays, but in the case of the 
red- and brown-burning structural-ware clays, the impurities furnish the most 
important data. We can but guess the fired color, strength, shrinkage, porosity, 
and vitrification range from the analytical data and for these properties, must rely 
on practical firing tests. If the chemical analysis is complete, however, it gives a 
good idea of the troublesome materials present, i.e.. those which cause early fusion, 
short vitrification range, scumming, and troublesome gases which delay oxidation. 
It happens that the usual commercial chemical analysis does not include carbon and 
sulphur and other troulilesome im])urities except when combined with water of 
chemical combination and called 'ignition loss' or 'volatile matter.' Likewise, a 
complete chemical analysis of the complicated silicate mixture called 'clay' is a 
difficult analytical procedure, and many hundreds of the analyses are inaccurate. 

"In studying clays of the whiteware and fire-clay type, a knowledge of the 
chemical composition is always desirable, but it must l^e assigned a secondary value 
because of the infiuence and modification of the physical iirojierties. Clays of the 
fire-clay type must primarily have a composition corresjionding to refractory chiys. 
But this is not enough. For instance, there are in the United States a large number 
of clays of practically the same composition as the imported European plastic fire 
clays, so highly prized for glass-pot, brass, and steel-crucible work, Ijut which fail 
completely in satisfying the physical, dry, and fired requirements. A cone fusion test 
costs less in time and money than a chemical analysis. The best way to determine 
the refractory value of a clay, having given only the chemical analysis, is to trans- 
late it to terms of cone fusion. 

"When physical tests of clay bodies are not satisfactory and changes are desired, 
the chemical analysis will often locate the trouble and indicate the proi)er remedy." 

Relatively few chemical analyses were made for the ])urpose of this 
report. A few typical samples were selected from those clays whose 
ceramic pro])erties were studied in the laboratory, and analyses were 
made in the Stanford University ceramic laboratory, using the methods 
recommended by the American Ceramic Society." Practically all of 
these analyses were made in duplicate or triplicate, and exceptional 
])recautions were taken to insure accuracy, especially in the determina- 
tions of alumina and silica, which are so often inaccurately rejiorted. 
A few analyses of laboratory samples were made by K. W. Baum, of 
the Stevenson Engineering Company. Analyses of various California 
clays were submitted by some of the clay manufacturers in the state, 
or were found in the literature. Where these a]iply to definite clay 
beds that were sampled by the author, the analyses are included under 
the clay sample number to which they refer. It must be understood, 
however, that such analyses were not made on the same sam])le as that 
which was tested in the laboratorv, lienee some of tliem do not correlate 



'Ceramics, pp. 45-4f.. McOraw-Hill Book Co., 1927. 

= Report of the Committee on Standards, Amer. Cer. Soc, reprint from Yearbook, 
1921-1922. 



CLAY RESOURCES AND CERAMIC INDUSTRY 253 

very well with the cei'ainic pfdiK-iiics noted. Another i^roup of 
analyses is inelnded of elays not slndii'd l)y the author. ]\Iost of these 
are from the S;ni Joa(|uin \'alh'y, and were coiil i-ihnted by K. W. 
Bauni. 

For convenience of reference, the analyses are f^rouped according 
to the clay classification used in this report, and are to be found near 
the end of Chaptei- V. 

Classification of Clays. 

Tlie clay classification used in this report is essentially that of 
Parmelee,^ but is presented in a simplified form. This classification is 
based upon the physical properties that determine the important uses 
of a given clay. The modified classification follows, witli notations to 
correlate it Avith that of Parmelce. 



I. CLAYS BURNING WHITE OR CREAM COLORED, NOT CALCAREOUS." 

A. Open-burning clays, i.e., having an apparent porosity of 6% or 

more at cone 15. 

The dividing line between oi)en-burning and dense-burning clays is 
placed at 5% in Par melee's classification. In this report the dividing 
line is at 6% in order to make some allowance for the more-rapid firing 
cycle used. 

Parmelee states "still distinctly ijorous at cone 15." 

1. Low strength, dry modulus less than 200 lb. per sq. in., e.g., 

residual kaolins and sandy fireclays. 

It is not clear whether Parmelee intends to include sandy fireclays in 
this gi'oup. 

2. Medium and high .strength, dry modulus exceeding 200 lb. 

])er sq. in., e.g., secondary kaolins. 

Open-burning clays are valuable in the manufacture of pottery 
becau.se of good color or good strength and good color. They are often 
highlv refraetorv, and mav be of value for special refractories. 

B. Clays burning dense, i.e., have less than 6% apparent ])orosity 

between cones 10 and 15. 

Parmelee states "becoming nearly or completely non-porous between cones 10 
and 15." 

3. Generally, but not always, refractory. 

Parmelee divides this group into three subdivisions, as follows: 

"a. Non-refractory clays. 

"3. Good color, medium to high strength, medium shrinkage. Uses: Pottery, 

including certain whiteware, porcelain, stoneware. 
"4. Poor color, medium to high strength, medium shrinkage. Uses: Stoneware, 

terra cotta, abrasive wheels, zinc retorts, face brick, saggers. 

"b. Refractory clays. 

"5. Good color, medium to high strength, medium shrinkage. Uses : Refractor- 
ies, especially for glass, if they do not overburden seriou.sly for 5 cones 
higher. Also uses as stated in Parmelee's No. 3." 



' Parmelee, C. W., and Schroyer, C. R., Further Investigations of Illinois Fire Clays, 
111. Oeol. Surv. Bull No. 38, pp. 278-9, 1922. 

^'The color limitations used in this report are given on page 251. 



254 DIVISION OF MINES AND MINING 

C. Dense-burning clays, i.e., Iiavini^ less than 6/^ apparent ])orosity 
between cones 5 and 10. 

Parmelee states ". . . become nearly or completely iioii-pni-inis between cones 
5 and 10 and do not ovei'burn seriously at 5 cones higher than the Itmperatiire at 
which minimum porosity is reached." 

4. Generally, but not always, refractory. 
Parmelee divides this group into five classes, as follows: 

"a. Non-refractory clays. 

"6. Good color, medium to high strength, medium shrinkage, usually reach 
minimum porosity between cones .5 and 8. Type: Ball clays. U.ses : 
I'ottery, whiteware, porcelain, and stoneware. 

"7. Poor color, medium to high strength, medium shrinkage. Uses : Stoneware, 

terra cotta, abrasive wheels, zinc retorts, face brick, saggers, 
"b. Refractory clays. 

"S. Non-porous or practically so at cone .'> ; do not seriously overburn for 12 

cones higher; highly refractory; softening point at cone :il or higher; 

bending strength minimum 325 pounds per square inch. Use: Graphite 

crucibles for melting brass, 
"fl. Non-porous at about 1275° C. (cone 8), not overflring at 1400° C. or higher. 

Strength and softening point as alaove. Use : Steel crucibles. 

"10. Become dense at about 1275° C. (cone 8). Do not overburn below 1425° C. 
Bonding strength, 250 pounds per square inch or higher. Softening point, 
cone 29 or higher. Use : Glass pots." 

II. BUFF-BURNING CLAYS. 

A. Refractory clays (softening point, cone 27 or above). 

a. Open-burning, i.e., having a porosity of 6% or more at cone 15. 

Parmelee states ". . . porosity of 5% or more at cone 15 or above." 

5. Low strength. Usually higli in non-])lastic material. 

6. ]Medium and high strength. 

Parmelee uses four subdivisions to cover (5) and (6) as follows: 

"Indurated — non-plastic or slightly plastic unless it lias been weathered. 

Type : Flint clay. 
"11. Normally aluminous; maximum alumina 40%. Uses: Refractories. 
"12. Highly aluminous; alumina exceeds 40%. Type: Diaspore clay. Uses; 

Refractories, abrasives. 

Plastic. 
"13. Normally siliceous; maximum silica not exceeding 65%. Uses: Firebrick 
and other refractory wares, terra cotta, sanitary ware, glazed and 
enameled brick (see specific requirements). 

"14. Siliceous; having a silica content above 659^. Type: Many of the New 
Jersey Are clays. Uses : Firebrick and other refractories." 

b. Dense-burning between cones 10 and 15, i.e., attaining an appar- 

ent porosity of 6% or less within that range. 

Parmelee states "... a minimum porosity of 5% or less . . ." 

7. Generally medium to high strength. 

This is Parmelee 's class 15, and is explained as follows: 

"15. Medium to high strength. Do not overburn for 5 cones higher than point 
of minimum porosity. Uses : Glass pots and other refractories ; al.so 
used for firebrick, saggers and miscellaneous refractories, architectural 
terra cotta, sanitary ware, enameled and face brick." 

e. Den.se-burning, i.e., attaining a porosity of 6% or less at cone 
10 or lower. 

Parmelee states "... a porosity of 5% or less . . ." 

8. Generally medium to high strength. 

Parmelee divides this grouj) into three classes, as follows : 
"16. See (Parmelee's) 8. 



CLAY RESOURCES AND CERAMIC INDUSTRY 255 

"17. See (Parnielee's) 9. 

"18. See (Tarmelee's) 10. 

"These tliree classes, 10, 17 and 18, are used also for ziiie retorts, firebrick, 
saggers, and miscellaneous refractories, architectural terra cotta, sani- 
tary ware, enameled and face brick." 

B. Xon-refrac'tory clays. 

a. Open-bnrniiijr, i.e., do not attain a porosity of fi'^J or less at any 

cone lower tlian cone 10. 

rarmelee states "... a porosity of 5'/^ or less 

!i. lli<.>-h or medium streiioth. Uses: Architectural terra cotta, 
stoneware, yellow ware, face brick, sanitary ware. 

10. Low strength. Use : Brick. ' 

Classes (fl) and (10) correspond to Parnielee's 19 and 20, 
respectively. 

b. Dense-burning, i.e., attain an ajiparent ])orosity of less than 6% 

at cones lower than 10. 

Parmelee states "... a porosity of les.s than 5% . . ." 

11. Generally medium or high strength. 

This is Parnielee's class 21, and is described as follows: 

"21. High or medium strength. Uses: Architectural terra cotta, stoneware, 
abrasive wheels, sanitary ware, face brick, paving brick." 

III. CLAYS BURNING RED, BROWN, OR OTHER DARK COLORS. 

A. Open-burning clays, i.e., those that do not attain an apparent i)or- 

osity of 6% or less at any temperature short of bloating or fusion. 

Parmelee states ". . . do not attain low porosity at any temperature short of 
actual fusion." 

12. ]\ledium or high strength. Uses: Brick, drain tile, hollow 

blocks, flower pots, pencil clays, ballast. 

1.3. Low strength. Use: Brick. 
Classes (12) and (13) correspond to Parnielee's 22 and 23, 
respectively. 

B. Dense-burning clays, i.e., those that attain an apparent jiorosity of 

6% or less at any temperature short of bloating or fusion. 

Parmelee makes no special statement to qualify the meaning of 
"Dense burning," but the definition follows from IIT-A, above. 

a. Having a long vitrification range (4 cones). 

Parmelee requires a 5-cone vitrification range, but the data of this 
bulletin do not permit such a .segregation, as only alternate cone num- 
bers were studied. 

14. Generally medium or high strength. Uses, if medium or high 
strength : Conduits, sewer pipe, face brick, roofing tile, 
paving brick, promenade tile, architectural terra cotta, and 
similar ware. If low strength: Common brick, floor tile, 
dust body in various wares. 



256 DIVISION OF MINES AND MINING 

Parmeloo makes two classes, 24 and 25, divided as to medium to hif?h 
strength or low strength, with the uses practically as indicated above. 

b. Having a short vitrification range (less than -i cones). 

15. Generally medium to high strength. Uses: Common brick, 
face brick, hollow tile, flower pots. 

Tliis is Parmelee's class 26, described as "High or medium strength," 
witii the same uses as given above. 

c. Fusing at a low temjjeraturc, api)roximately cone 5, to foi-m a 
glass. 



&^ 



16. Slip clays. 

This is Parmelee's class 27. No clays were found in California in 
this class, but room is left in the classification in case any are found in 
the future. 

IV CLAYS BURNING DIRTY WHITE, CREAM WHITE, OR YELLOWISH 

WHITE. 

17. Generally containing calcium or magnesium carbonate or 

both. Seldom reach very low porosity. Have a very short 
heat range. Use : Common brick, or may be worthless. 

This is essentially Parmelee 's class 28, which is described as follows : 

"28. Containing calcium or magnesium carbonate or both. Never reach very 
low porosity. Have a very short heat range. Use : Common brick." 

The foregoing classification is not presented as being preferable for 
general use to Parmelee's more complete one, but it serves the i)ur- 
poses of this bulletin better, in that the tests on the California clays 
were not sufficiently comprehensive to permit the degree of refinement 
of clay classification that characterizes Parmelee and Schroyer's report. 
For example, bonding-strength determinations are necessary in order 
to segregate Parmelee's classes 8, 9 and 10, and 16, 17 and 18; firing 
tests to cone 19 or 20 are necessary to fully determine the properties 
of a clay for his classes 5, 8 and 16 ; chemical analj^ses are necessary in 
order to segregate his classes 11, 12, 13 and 14, and firing to each cone 
number, instead of to alternate cone numbers, is required in order to 
separate the red-burning clays having a long vitrification range from 
those having a short range. To complete the data for a satisfactory 
allocation of clays according to Parmelee's classification, would have 
required more than twice the amount of work than that represented by 
the testing for this bulletin, without considering the extra field work 
that should be entailed to secure thoroughly representatiA'e samples of 
entire clay beds. It is questionable if 50-pound field samples, unless 
obtained by quartering down a number of larger channel-cut samples, 
or by combining a number of coredrill samples, are sufficiently reliable 
to warrant more elaborate tests than have been made. 




»i-.T:in i -NTl-* /ir-D A HTK' T M HT T>iTR V Ji'^l 



ed. The 
:'y trans- 
he clays 
ord IJiii- 
11(1 dried 
v'ho ^vish 
ew clays 
)spectin<i,' 

that are 
Lii plastic 
a. Tests 
data are 
) class 1, 
davs antl 
Wilson. 1 
the clay 
)n of the 



vYS. 

15. 



. "E-101 
is princi- 
ns 33.0% 
e enough 
len fired. 
, and the 
Dry and 
e cone 1, 
f" tints, 
the hard- 
^e, plastic 
-29. The 
)e washed 
specking, 
: vitrifica- 
ni found, 

). "E-102 
but is of 
the fired 
colors are darker. The percentage remaining on 2UU-mesh is 22.6. 

' The Clays and Shales of Washington, Their Technology and Uses. Bull. Univ. of 
Wash., Engin. Exp. Sta.. No. 18, p. 203, ct seq. 

17 — .'')4979 



256 DIVISION OP MINES AND MINING 

Panneloo makes two classes, 24 and 25, divided as to medium to hig-h 
streiiKtIi or low strength, with the uses praetieally as indicated above. 

b. Having a short vitrification range (less than 4 cones). 

15. Generally medium to high strength. Uses: Common brick, 

face brick, hollow tile, flower pots. 

Til is is Parmelee's class 26, described as "High or medium strength," 
witii the same uses as given above. 

c. Fusing at a low temperature, ap|)r()xiiiuite]y cone 5, to form a 

glass. 

16. Slip clays. 

This is Parmelee's class 27. No clays were found in California in 
this class, but room is left in the classification in case any are found in 
the future. 

IV CLAYS BURNING DIRTY WHITE, CREAM WHITE, OR YELLOWISH 

WHITE. 

17. Generally containing calcium or magnesium carbonate or 

both. Seldom reach very low porosity. Have a very short 
heat range. Use : Common brick, or may be worthless. 

This is essentially Parmelee's class 28, which is described as follows: 

"28. Containing calcium or magnesium carbonate or botli. Never reach very 
low porosity. Have a very short heat range. Use : Common brick." 

The foregoing classification is not presented as being preferable for 
general use to Parmelee's more complete one, but it serves the i)ur- 
poses of this bulletin better, in that the tests on the California clays 
were not sutBciently comprehensive to permit the degree of refinement 
of clay classification that characterizes Parmelee and Schroyer's report. 
For example, bonding-strength determinations are necessaiy in order 
to segregate Parmelee's classes 8, 9 and 10, and 16, 17 and 18; firing 
tests to cone 19 or 20 are necessary to fully determine the properties 
of a clay for his classes 5, 8 and 16 ; chemical analj^ses are necessary in 
order to segregate his classes 11, 12, 13 and 14, and firing to each cone 
number, instead of to alternate cone numbers, is required in order to 
separate the red-burning clays having a long vitrification range from 
those having a short range. To complete the data for a satisfactory 
allocation of clays according to Parmelee's classification, would have 
required more than twice the amount of work than that represented by 
the testing for this bulletin, without considering the extra field work 
that should be entailed to secure thoroughly representative samples of 
entire clay beds. It is questionable if 50-pound field samples, unless 
obtained by quartering down a number of larger channel-cut samples, 
or by combining a number of coredrill samples, are sufficiently reliable 
to warrant more elaborate tests than have been made. 




Photo No. 711. Cabinet of fired test pieces, ceramic laboratory, .Stanford University. 



54979 — facing iiage 257 



256 

Parmelee mak 
strenytli or low 

b. Having j 

15. Genei" 

face 

This is Parme 
with the same ii 

c. Fusing a 

glass. 

16. Slip el 

This is ParnK 
this class, but ix 
the future. 

IV CLAYS BUR^ 

17. Generf 

both 
heat 

This is essenti 

"28. Containlr 
low poi 

The foregoing 
general use to '. 
poses of this bu 
were not suffieie 
of clay classifica 
For example, b( 
to segregate Pai 
tests to cone 19 
of a clay for his 
order to segrega 
number, instead 
separate the red 
those having a ! 
allocation of cla 
required more tl 
the testing for 1 
that should be e 
entire clay beds 
obtained by qua 
or by combining 
to warrant more 



CLAY RESOURCES AND CERAMir TXDUSTRY 257 

Chapter V. 

RESULTS OF LABOKATORY TP]STS. 

Table No. 11 is a complete classified list of all samples tested. The 
fired test i)ieces, samples of dried bars fsalvaf^ed from the dry trans- 
verse-.stren<?tli tests), and lumj) and f^round sam])les of all the clays 
are kept in an accessible file in the ceramic laboratory at Stanford Uni- 
versity. Photo No. 70 shows the case eontainin*? the fired and dried 
test pieces. These files may be of interest to clay workers who wish 
to select clays for specific purposes, and it is hoped that new clays 
can be added from time to time as they are disclosed in i)i'ospectin<»' 
and mining operations. 

Tests are included on two clays from outside of the state that are 
being used in local plants. These are No. 56 in class 7, a German plastic 
fireclay, and No. 59 in class 2, the Edgar kaolin from Florida. Tests 
were made on English china and ball clay but the detailed data are 
not included herein. The china clay was found to belong to class 1, 
and tlie ball clay belongs in class 4. The data on tlie English clays and 
the Edgar kaolin correlate closely with tliose given by Hewitt Wilson.' 

The page numbers cited in the descriptive text, following the clay 
sample nundjer, refer to the pages containing the description of the 
deposit from whicli the sample was taken. 

I. WHITE- OR CREAM-BURNING NON -CALCAREOUS CLAYS. 
A. Open- Burning, More Than 6% Apparent Porosity at Cone 15. 

1. Low Strength. 

No. 11 (p. 168). Riverside County. Alberhill C. & C. Co. "E-101 
China Clay." This is a sandy clay of the kaolin type, and is princi- 
pally used in stoneware bodies. See also No. 12. It contains 33.0% 
of 4" 200-mesh sand, which is mainly quartz, but there are enough 
ferro-magnesian minerals to cause red and black specks when fired. 
The plasticity is good, though short, the dry strength is low, and the 
dry condition is weak, crumbly and sandy. The colors are: Dry and 
w^et, yellowish white; from cone 010 to cone 1, 13"f; above cone 1, 
butf-white, considerably nearer to white than Ridgway's "f" tints. 
Finger-nail hardness is developed at cone 04, and at cone 13 the hard- 
ness is still slightly less than steel. The total linear shrinkage, ])lastic 
basis, at cone 15, is 11.4%. The softening point is cone 28-29. The 
best firing range is from cone 3 to cone 13. The clay covdd be washed 
to remove non-plastic impurities, which Avould eliminate the specking, 
and increase the plasticity and strength, as well as lower the vitrifica- 
tion point, but as no large bodies of this variety have been found, 
washing at the mine is not warranted. 

No. 12 (p. 163). Riverside County. Alberhill C. & C. Co. "E-102 
China Clay." This is .similar in eA'ery respect to No. 11, but is of 
slightly poorer quality, as it contains more impurities, and the fired 
colors are darker. The percentage remaining on 200-mesh is 22.6. 

> The Clays and Shales of W'ashington, Their Technology and Uses. Bull. Univ. of 
Wash., Engin. Exp. Sta., No. IS, p. 20.3, ct seq. 

17—54979 



258 



DIVISION OP MINES AND MINING 






« c 



CO '— '-0 »c ^ cc tf; CI 

-*< *t" •-■ — ' ;D O -.^ 









^^ ^« r-< _ c>l C^l C^l 7-1 C-i 



^- d ci t^ C-) ci -r i^ oo 00 o o ^- ^H 



O 






1^ (M C-1 ^- ^- OO 00 CO 

I ^ C-1 CC t^ C5 ^- »0 

•— -- ^ « C-1 <M 



3 bC laj 

■-51H c 



«— ic>iiMcoffO-^':o^r-oO'— • — — — li^t^i-oocxioocio — — — Ti»co 
_H ^^ *-^ .-^ _ .^ _. *_ -^ ^« _ ^H ^H l^) c-i rt ci C) 'M C4 



E 






PQ 



CQ 



-^ I 

■to 

+ s 

O 






•—''—' 1—1 (M C-l C-1 



6 ^ 



CiiC^-^iOOi-^tCOOCrcOiCCCCO 
,_ ^H — 1— . ,— . (M C-l (M 



-f 



P:i 



Q o 



C*IfMCO'^TfiO»CW5b-0»000 






O 



S «^ 



^ bC 



co05X)Oc*3»C'— ■oroc;co'-0't<ccc;o»c:Ot^QOC. cc-^ — -^ 

.— .CCIOOOOOOOO"— 'CO-t"»0»00'— '^^CC-*■^■^■^■^^C^Ct-r-- 
^-, .— . .— I 1— . 1— I ,-. C^ (M M C^ -M (M (M (M (M C^ IM w w 



— "^^cccc>'^^-t-^oooooiOiOOc*:^co■^lCC:>l^•cco:d- 



.-H(Mi:o^t^t^t^r^oooooc^ico-^-^'^o;C5ecc*3co-^»(^t--oooo 






If? CO o 
!M "^ Tt< 

^ -^ (M 



PQ « 



+ \ 






ocooo 0-* eo 

t^ C5 Oi W -^ t^ 

^ <— "CM 



C ^ 



^ « 



'-•Mr-OOClCO'^'— 'CCOOCi-^CiOO^iCOOCTltC^r^CiOO 

.-,— icccocoococ;0'M(Mro»o:cdC. dOOcococo»o*.o 

,„ _< ,_ .-4 .^ ^« ^M 1^ -« C^l CI <M "M -M C-1 iM 



CLAY RESOURCES AND CERAMIC INDUSTRY 259 

Finger-nail liardness is developed at cone 02, and knife hardness at 
cone 12. The total linear slii-inkaue, plastic basis, at cone 12 is 12.2%. 
The softeninj; point is cone 2()-27. The best firing range is from 
cone 3 to cone ]:]. 

No. 37 (p. 201). San Diego ("oiinty. El ("ajon Mountain. The 
sample is rejiresentative of the more kaolinitic ])liase of a residual 
kaolin dejiosit, of which No. 38 is a more general sam])le. It is not 
entirely free from fine (piartz and feldsi)ar grains, and also contains 
some ferro-magnesian minerals whicli ajjjjcar as numerous black 
specks in the fired clay. The proi)ortion of + 200-mesh sand is 13.0%. 
The i)lasticity is workable, but is weak and sticky. The dry strength 
is medium low, and in the dry state the sample is soft and crumbly. 
Slow drying is necessary to avoid drying cracks. The colors are nearly 
white, with a ])inkish tinge at low cone numbers, and a yellowish tinge 
when fired above cone 1. Finger-nail hardness api)ears below cone 010, 
and steel hardness at cone 1. Fine cracks ai)pear at high tem])eratures. 
The total linear shrinkage, ])lastic basis, at cone 15, is 20.9'/ . The 
softening point is cone 34. This clay could be washed to remove the 
ferro-magnesian minerals, but the deposit is too small and irregular, 
and too isolated for co)nmercial operations. It was at one time mined 
on a small scale and the clay was used in the manufacture of Faience 
tile, and some attemi^ts were made to use the material as a substitute 
for English china clav in whiteware bodies. 

No. 38 (p. 201). San Diego County. El Cajon IVIountain. This is 
a general sam])le of the residual kaolin dejiosit from which sample 
No. 37 was taken. It contains 57.0' ; of + 200-mesli grains, most of 
which are undecom])()sed (puirtz and feldsi)ar, but there is a smaller 
proportion of ferro-magnesian minerals than in sample No. 37. It 
effervesces slightly in hydrochloric acid. The plasticity is poor, the 
dry strength is nu'dium ]ow% and the dry and fired structure is coarse 
and granular. The colors closely approximate white, with a faint ])ink 
hue. Steel hardness is not developed at cone 13. The total linear 
shrinkage, i)lastic basis, at cone 13, is 4.75%. The softening point is 
cone 32-33. The best structure and color is obtained by firing above 
cone 7. The amount of kaolin thai could be extracted by wasliing was 
not determined, but not over 20% could be expected. 

No. 62 (i). 145). Orange County. East of San .Juan Capistrano, 
on the O'Neill rancli. "White bone." This is a ])lastic fireclay that 
usually contains over 45/{ of alumina. Although the pisolitic struc- 
ture of tlie raw clay is lacking, or is but poorly (Un'elo])ed, it may be 
classed as a bone clay on account of its high alumina content, and its 
ceramic properties. The ])lasticity is short, the dry strength is low, 
and the dry condition is medium hard, medium-grained, and open- 
textured. The residue on 200-mesh is 46.4%. The colors are nearly 
white througliout, with a pink hue at low firing temperatures, changing 
to yellowish white at higher firing temperatures. Scattering yellow and 
brown iron specks ai)i)ear at high tem])eratures. Finger-nail hardness 
is obtained below cone 010, and steel hardness develops at cone 1. Light 
crow-foot cracks appeared in all jiieces fired above cone 1. The fired 
texture is granular and open. The total linear shrinkage, plastic 
basis, at cone 15, is 17.5 ^r . The softening point is cone 34. The best 



260 DIVISION OP MINES AND MINING 

firing range is above cone 1, and well vitrified structures are obtained 
at cone 11 or above. 

No. 6:K 61 and ;:268 (p. 140). Orange County. 12 m. E. of El Toro. 
Hunter ranch deposit. These three samples, from different portions 
of the Hunter ranch, are practically identical in all respects. The 
material consists of an admixture of high-grade china clay and quartz 
sand, in the proportion of approximately 35% clay. No. 63 contains 
54.4% of -)- 200-mesh sand, and No. 64 contains 63.6%. In places, a 
small amount of hornblende occurs in the clay, which must be removed 
by washing, if the clay is to be used in whiteware bodies. The most 
important use at ])resent is in the manufacture of high-grade fire brick, 
at the plant of the American Refractories Co., of Los Angeles, but 
Mr. H. F. Coors has stated ^ that he believes that the washed clay could 
be substituted in any ceramic body to replace 75% of the English china 
clay now in use. The by-product from washing would yield a quartz 
sand, which, if hornblende is removed by tabling, would be suitable for 
glass manufacture. All three samples were tested by the usual methods, 
without washing. The plasticity is weak, the dry strength low, and 
the dry condition is coarse, sandy, open and friable. The colors are 
nearly white, with a pinkish hue at low firing temperatures, changing 
to yellowish above cone 1. Steel hardness is not developed within the 
firing range employed. The fired structure is coarse, granular, and 
w^eak. The total linear shrinkage, at cone 13, is 4.0% for No. 63, 5.1% 
for No. 64, and 5.2% for No. 268. The softening point in all cases is 
cone 33. 

No. 91 (p. 171). Riverside County. Alberhill. G., McB. & Co. 
"Main Tunnel Sand." This belongs to the same group as No. 13, 15, 
29, 84, 91, 96 and 229, but has a larger proportion of sand than any of 
the others. It contains 55.0% of -I- 200-mesh sand. The plasticity is 
weak, the dry strength is medium low, and in the dried state it is 
friable, coarse-grained and open-textured. The colors are : dry, V^""! ; 
wet ll'"'\; cones 010 to 13, pinkish white at the lower temperatures, 
changing to yellowish w^hite at the higher temperatures. Steel hard- 
ness appears at cone 9. The fired structure is sound, and coarsely 
granular. Tlie total linear shrinkage, plastic basis, at cone 13, is 3.1%, 
which is a slight expansion over the dried condition. The softening 
point is cone 30-31. This material is used with more plastic clays in 
firebrick and terra cotta mixes. 

No. 103 (p. 171). Riverside Countv. Alberhill. G., McB. & Co. 
''Sloan Bone." See also No. 74, 86, 87, 231, and 232 in class 5, and 
No. 98 in class 3. This is a white bone clay of exceptional purity. It 
contains 46.2% of -|-200-mesli material. The plasticity is weak, the 
dry strength is low, and in the dried condition it is soft, friable, and 
open-textured. Tlie colors are : dry, grayish white ; wet, 17'"f ; cone 010, 
15"f; cones 08 to 13, fades to pinkisli white at cone 1, then to 
yellowish white at cone 13. Finger-nail hardness is present at cone 
010, and steel hardness at cone 3. All fired test pieces are hair-cracked, 
and one or two of them broke into two pieces. Less than 10% absorp- 
tion is obtained at cone 9. The total linear shrinkage, plastic basis, at 
cone 15, is 16.9%. The softening point is cone 35. 

' Private communication, July, 1925. 



CLAY RESOURCES AND CERAMIC INDUSTRY 261 

No. 128 (p. 54). Amador County. lone. Arroyo Seco Grant. 
"Shepard Sand." Tlii.s is one of the 'fire-sands' for which the lone 
district is noted. The material consists of a fine-nrrained quartz-mica- 
feklspar sand with sufficient fireclay to render it -weakly plastic. It 
contains 48.4% of -|-200-mesh sand, and a lii<;li percentage of the — 200- 
mesli material is non-plastic. The dry strength is low, and in the dried 
condition it is very soft. Tlie colors are nearly white with a slight 
yellowish hue throughout. Finger-nail hardness appears at cone 02. 
but steel hardness is not developed on firing to cone 15. The fired 
structure is sound, and fine-granular. The total linear shrinkage, 
plastic basis, at cone 15 is 6.7%. The softening point is cone 32. The 
sand has important uses as an ingredient in fire brick, terra cotta, 
pottery, etc. 

No. 129 {\).Q2). Amador Count}'. lone. "Newman Sand." This is 
almost identical in its properties to No. 128, except that it contains a 
lower percentage of fluxing impurities, and has a softening point of 
cone 33-34. The percentage of -[-200-mesh sand is 55.4. 

No. 134 (p. 58). Amador County. Tone (Carbondale). X. Clark & 
Sons. "Clark Sand." This is fire-sand, nearly identical in its prop- 
erties to No. 128 and 129, with a softening point of cone 32-33. It 
contains 55.8% of -(-200-mesh sand. 

;\^o. i55 (p. 137). Nevada County. Wolf. Coe property. Pine Hill 
Mine. See also No. 160. 166 (class 11), and 167 (class 10). This is a 
plastic impure kaolin that has not yet been used commercially. It 
contains 12.4% of -|-200-mesh sand. The plasticity is fair, thougli 
somewhat 'rubber}^' and Aveak. The dry strength is medium low, 
and in the dried condition it is medium hard, fine-grained, and open- 
textured. The colors are: dry, yellowish-white; wet, 19"f; cone 010, 
17"f, decreasing with increasing temperature to yellowish white at 
cone 1 and above. Steel hardness is developed at cone 5. The fired 
structure is sound, and stony, except for light liair-cracks at cones 11 
and 13. The fired surface texture is smooth. The total linear shrink- 
age, plastic basis, at cone 15 is 18.8%. The softening point is cone 32-33. 
The best firing range is from cone 1 to above cone 13. If this clay were 
found in sufficient abundance, it might find important uses in the 
manufacture of pottery, tile, and fire brick. 

No.l60{\).l'il). Nevada County. Wolf. Coe property. Pine Hill 
Mine. See also No. 159, 166 (class 11), and 167 (class 10). This is 
similar to No. 159, but contains more non-plastic matter, and burns to 
a whiter color. The plasticity is smooth, but not strong, the dry 
strength is low, and in the dried condition it is soft-fine-grained, and 
open-textured. The colors are : dry, 13"'f ; wet, 13'"d ; cones 010 to 1, 
l'"f; cones 3 to 9, whiter than 9'''f ; cones 11 and 13. grayish white. 
Steel hardness is not developed within the firing range studied, up to 
cone 15. The fired structure is sound, fine-granular, and smooth- 
textured. The maximum total linear shrinkage, plastic basis, at cone 
13, is 11.7%. The softening point is cone 32-33. If it could be placed 
on the market cheaply, this clay would find use in pottery, tile, and 
fire brick manufacture. 

No. 190 (p. 133). Napa County. Calistoga. Clark and Marsh 
kaolin. This is a residual kaolin, hand-sorted to remove iron-stained 



262 DIVISION OF MINES AND MINING 

impurities. A larj^e proportion of the sample consists of non-plastic 
kaolin in the form of hard jirains, and some quartz is present. The 
percentage remaining on 200-mesh is 41.4. The plasticity is poor, 
the dry strength is medium low, and in the dried condition it is medium 
hard, coarse-grained, and open-textured. The colors are nearly white 
throughout, with a slight pinkish hue in the raw condition and when 
fired below cone 3, and a slight yellowish hue when fired above cone 3. 
The fired structure is weak, granular, rough-textured, and with a 
tendency to crack. Steel hardness does not develop within the firing- 
range studied, up to cone 15. The total linear shrinkage, plastic basis, 
at cone 15, is 12.0Vc. The softening point is cone 31-32. 

Professor Hewitt Wilson tested a sample from this deposit, and has 
supplied tlie following notes :^ "The fusion was cone 34, indicating a 
high degree of purity, and a high degree of refractoriness for a kaolin 
fire brick, sui)erior to that now on the market. 

"For white chinaware, it will be necessary- to use 15 to 20% of a 
plastic white-burning clay like a ball clay, 20-25% Calistoga clay, 
20% feldspar, and 35-40% ground (|uartz. This gave (with Washing- 
ton materials) satisfactory results as to molding, drying, firing and 
white color." 

It is ajiparent that the sample tested by Prof. Wilson differed some- 
what from that tested by the writer. 

No. 194 {\x 221). Sonoma County. Glen Ellen. J. H. Weise prop- 
erty. This is a white-burning kaolin, with fair plasticity and low dry 
strength. It contains 34.8% of 4-200-mesh material. In the dried con- 
dition it is soft, medium-grained, and open-textured. Approximately 
25% of quartz sand is present, together with a small proi)ortion of 
ferro-magnesian mineral grains. The colors are: dry, ll'f ; wet, ll'd; 
cone 010, 9"f, gradually fading to nearly white at cone 7 and higher, 
except for widely scattered black specks. Steel hardness is not devel- 
oped within the firing range studied. The fired structure is sound, 
weak, granular, and open, and the surface texture is slightly rough. 
The total linear shrinkage, plastic basis, at cone 15, is 6.1%. The 
softening point is cone 32. This clay could be Avashed free from quartz, 
and used in the manufacture of a kaolin fire brick, but would recjuire 
the addition of a refractory bond clay in order to secure sufficient dry 
and fired strength. It might also be used in tile and porcelain bodies, 
in place of a ]iortion of the china clay usually used, if the ferro-mag- 
nesian minerals were removed by washing. 

No. 195 (p. 227). Sonoma County. Glen Ellen J. H. Weise 
property. This is a hand-picked sample of the whitest material in 
the pit from which No. 194 was taken. It is more plastic than No. 194, 
has better dry strength, better fired color, and higher refractoriness. 
The residue on 200-mesh is 30.2%. Very few iron specks can be found. 
The total linear shrinkage, plastic basis, at cone 15 is 9.9%. The soften- 
ing point is cone 33. A peculiarity of both of these samples is that the 
firing shrinkage is greater at cone 9 that at cone 13, but the shrinkage 
increases again at cone 15. 

No. 208 (p. 57). Amador County. Tone. Wm. Haverstick. This 
is a sample of lone sand supplied by Mr. Haverstick. It is somewhat 

• Personal communication, Septem.ber, 1925. 



(LAY KESOUKCKS AM) CERAMR IXDLSTUV 263 

more jilastic and burns whiter than other sami)les that were tested 
(see No. 128. 12!) and l."U). Tlie total linear shrinka^n', plastic basis, 
at cone 15, is 8.6/< • The softeninj,' point is cone 32. The .sample eon- 
tains 28.27o of +2()0-mesh sand. 

No. 20!> (p. .")})). Aiiiadoi- County. lone. Sample sii|)plie(l by 
AVm. Haverstick. This is a sand containinp: a hi<>:her proportion of 
day than tlie more typical samples (see No. 128, 129 and 134), hence 
))ossessiii«>' b(4ter pla.sticity and ai-eater shrinkap-o. The i-esidno on 
2()()-mesh is 1.1.8 /^ . The color is ^^ood, bnt <>'reen scuniminji' is esi)e- 
cially noticable. Steel hardness is develo])ed at cone 9. The total linear 
shrinkage, ])lastic basis, at cone 1.") is lo.2%. The softening point is 
cone 32. 

No. 235 ()). 70). Calaveras Connty. Valley Springs. Texas Alining 
Comjtany. This is a kaolini/ed sei-icite-talc schist that has sufficient 
jdasticity to permit molding or pressing. The dry strength is low, and 
in the dried condition it is soft and friable. The colors are: dry, 17"f ; 
Avet, 15"d; cone 06 to 1, 13"f; cones 5 to 13, pinkish-white. Finger- 
nail hardness is developed at cone 1. The fired strnctnre is sonnd, 
weak, and fine granular. The total linear shrinkage, ])lastic basis, at 
cone 13, is 14.6'/f ■ The softening point is cone 30-31. The material 
could be used as a noni)lastic ingredient in white flooi- and wall tile. 

No.2S6{\^.m). Calaveras County. Nigger Hill. "Kaolin." This 
is an impure kaolin that has resulted from the alteration of a sericite- 
talc schist. The ])lasticity is fair, the dry strength is low, and in the 
dried condition it is soft, friable and fine-grained. The colors are: 
dry, nearly white; wet, grayish w^hite ; cones 06 to 13, nearly w^hite. 
Finger-nail hardness is developed at cone 06, and steel hardness at 
cone 5. The fired structure is sound, medium strong, and fine-granu- 
lar. The total linear shrinkage, ])lastic basis, at cone 13, is 20.9%. 
The softening ])oint is cone 29-30. The material can be used as a non- 
plastic ingredient in white tile bodies. 

No. 237 (p. 68). Calaveras County. Nigger Hill. Sericite-talc 
schist. This is similar to No. 235, but contains a slightly higher percent- 
age of iron. The total linear shrinkage, plastic basis, is 14.5% at cone 
13. The .softening point is cone 27-28. 

No. 2'>9 (\). 45). Alameda County. Tesla. This is a white-buining 
fireclay with excellent ])lasticity and medium low dry strength. It 
contains 1.6% of -(-200-mesh sand. In the dried condition it is soft, 
fine-grained and close-textured. The colors are: dry, 17'"f ; wet, 15"f ; 
cones 010 to 04, ])inkish white; cones 02 to 9, nearly white; cones 11 to 
15, yellowish white. Steel hardness is develo])ed at cone 3, and less 
than 10% absorption at cone 11. The fired structure is stony and 
smooth-textured. A few small cracks appear in some of the fired test 
pieces. Slight blistering is noted at cone 13. The total linear shrinkage, 
plastic basis, is 20.4% at cone 15. The softening point is cone 34-35. 
This is one of the best fireclays tested and if it can be found in com- 
mercial quantities, it wall undoubtedly be in great demand for fire- 
brick, whiteware, and tile. 

No. 268. This sample has already been described (see No. 63, p. 260) . 



264 DIVISION OP MINES AND MINING 

2. Medium to High Strength. 

No. 15 (p. 163). Riverside County. Alberhill C. & C. Co. "Select 
Main Tunnel." See also No. 13 (class 7) and 29. This clay is hand 
sorted from the main tunnel fireclay bed, in order to make a marketable 
grade that is intermediate in quality between the run-of-mine material 
(No. 29) and the extra-select main tunnel clay (No. 13). It is used 
principally in the manufacture of tire brick. It is fine-grained, with 
excellent plasticity, medium high dry strength, and good dry condition. 
It contains 11.3% of plus 200-mesh sand. The colors are: dry, 13"'f ; 
Avet. 17""b; fired, cream white, considerably whiter than Ridgway's 
"f " tone. Finger-nail hardness is developed below cone 010, and steel 
hardness is reached at cone 5. The total linear shrinkage, plastic basis, 
at cone 15 is 11.7%. The softening point is cone 30-31. The best firing 
range is from cone 5 to cone 15. 

No. 28 (p. 163). River.side County. Alberhill C. & C. Co. "SII-3." 
This is a clay with excellent plasticity, medium dry strength, and a fine 
grained, clo.se-textured dry condition. It contains 11.2% of -|-200- 
mesh sand. It is used for art title and architectural terra cotta. The 
colors are: dry, 13'"f; wet, 13'''d; cone 010 to cone 1, 17"f; cone 3 
and above, the pink gives way to yellow, and the tone is nearer white 
than Ridgway's "f" tone. Finger-nail hardness is developed below 
cone 010, and steel hardness at cone 7. Vitrification is not well 
advanced at cone 13. The total linear slirinkage, plastic basis, at cone 
13, is 10.0%. The softening point is cone 30. The best firing range is 
from cone 3 to cone 13 or above. If this clay were more plentiful, it 
would find a wide use in art title, terra cotta, and similar products. 

No. 29 (p. 163). Riverside County. Alberhill C. & C. Co. "Main 
Tunnel." See also No. 13 (class 7) and No. 15. This is the run-of-mine 
main tunnel fireclay, and differs from the selected varieties, No. 13 and 
No. 15, mainly in that it contains more sand and more coloring matter. 
The percentage remaining on 200-mesh is 37.2. The clay is widely used 
in fire brick, art title, architectural terra cotta, and for similar purposes. 
It has a good working plasticity, but the plastic strength is low. In 
the dry condition it is medium hard, with a coarse, open texture, and 
the dry strength is medium. The colors are: dry, 17"'f; wet, 17"'d; 
cones 010 to 04, 13"f ; cones 02 to 3, 13"'f ; cones 5 to 13. nearer white 
than 17'"f. Finger-nail hardness appears below cone 010, but steel 
hardness does not develop within the firing range of the tests. The 
total linear shrinkage, plastic basis, is 5.6%, at cone 15. The softening 
point is cone 30-31. The best firing range is from cone 5 to cone 15 
and above. 

No. 44, 45 and 57 (p. 196 and p. 194). San Bernardino County. Hart. 
No. 44 is from the lower tunnel, and No. 45 is from the upper tunnel of 
the deposit owned by the Standard Sanitary Manufacturing Co., while 
No. 57 is from a similar deposit in the same district, owned by H. F. 
Coors. They are white-burning clays that may be classed as china- 
ball clays, as they possess the properties of a mixture of china and ball 
clays as usually used in porcelain and whiteware bodies. No. 44 con- 
tains more quartz than the other two samples. It contains 33.4% 
of +200-mesh material. No. 45 contains 28.2 ^( , and No. 57 contains 
21.8%. All three samples contain a small proportion of undecomposed 



CLAY RESOURCES AND CERAMIC INDUSTRY 265 

ferro-magncsiaii minerals, ^v}lich is readily removed in the usual 
processes of slip preparation. Enough colloidal iron is present in No. 
44 and 45 to impart a yollowisli tint to the tired clay, hut No. 57 is the 
whitest clay that was tested, and has a distinctly better color tlian 
English china clay or Edjrar (Florida) kaolin. The plasticity of all 
three samples is excellent and the dry strength is exceptionally high. 
Finger-nail liardness is present in tlie dry state, and steel hardness 
develops at cone 06. Although the softening point is cone '-iO for No. 44 
and 45, and cone 29 for No. 57, bloating begins at cone 11 to 13. The 
maximum total linear shrinkage, plastic basis, is 9.5% at cones 3 to 
5 for No. 44. IG.O'r at cone 15 for No. 45, and 14.8% at cone 11 for 
No. 57. Small tiring cracks are found in some of the test pieces of No. 
45, fired above cone 3, but all test pieces of No. 44 and 57 are sound. 
The tendency of these clays to bloat when used in porcelain bodies to 
be fired above cone 8 is their most serious defect, and has prevented 
their continued use in two sanitary ware plants that formerly used 
them in place of Eastern or English clays. No. 44 and 45 are now used 
in the enameling plant of the Standard Sanitary Manufacturing Co., 
and No. 57 is used in the manufacture of electrical and plumbing 
accessory porcelain, in tlie jjlant of the 11. F. Coors Co. The best firing 
range is from cone 06 to cone 8 to 11. 

No. 59. Edgai- kaolin (Florida), used by the American Encaustic 
Tiling Comi)any. This is a white-burning kaolin, with smooth and 
strong plasticity, medium dry strength, and a soft, fine grained, 
close-textured, dry condition. Some finely divided mica is ]-)resent, 
but the sample contains onl,y 0.6% of 4-200-mesh material. A faint 
pink color can be noted when fired below cone 1, but at higher 
temperatures the color closely approximates pure white. Finger-nail 
hardness is ohtaiiuMl below cone 010, and steel hardness develops at 
cone 3. The fired structure is stony, and with the firing schedule used, 
all test pieces had deep crow-foot cracks, which, however, were not 
continuous enough to cause disintegration. The total linear shrinkage, 
plastic basis, at cone 15 is 24.8%. The softening point is cone 34r-35. 
The best firing range is from cone 1 to above cone 15. 

-Vo. .W fp. 171). Riverside Countv. Alberhill. G.. McB. & Co. "Main 
Tunnel Fire Clay." This should be compared with No. 13 and 229 
(class 7), 15, 29, 84 (class 6), 91 (class 1), and 93, post. No. 90 con- 
tains 17.4% of +200-mesh sand. The plasticity is excellent, the dry 
stre?igth is medium, and in the dri(Ml conditiou it is medium hard, fine 
grained and close-textured. The colors are: dry, 17""d; wet, neutral 
gray k; cones 010 to 13, pinkish white, changing at the higher tempera- 
tures to yellowish white. Finger-nail hardness is developed below cone 
010, and steel hardness appears at cone 11. Tiie fire structure is sound 
and fine-granular. The total linear shrinkage, plastic basis, at cone 
13, is 10.7%. The softening point is cone 31. 

No. 93 (p. 171). Riverside County. Alberhill. C, Mc.B. & Co. "Select 
Main Tunnel." The properties of this clay are almost identical with 
those of No. 90, except that it is finer-grained, has lower porosities, and 
the colors are slightly whiter throughout. The sample contains 1.0% 
of 4-200-mesh sand. Steel hardness is developed at cone 1. The total 
linear shrinkage, plastic basis, at cone 13, is 11.8%. The softening 



266 DIVISION OF MINES AND MINING 

point is cone 80-31. It is a useful clay for terra cotta, faience tile, 
face brick and fire brick, and may be used in stoneware and pottery. 

No. 109 (p. 176). Riverside County. Alberliill. P. C. P. Co. "Doug- 
las ]\Iain Tunnel." This is from an extension of the formation from 
which the Alberliill Coal and Clay Company's "Main Tunnel" clays 
are mined, see No. 13 (class 7), lo, and 29, but is more closely related 
to the G., McB. Co. "Main Tunnel Fire Clay," No. 90, in its^ ceramic 
properties. It contains 22.6'/ of -|-200-mesh quartz sand, and a small 
proportion of ferro-magnesian minerals. Tlie plasticity is very good, 
and the dry strength is medium high. In the dried condition it is 
medium hard, and has a medium fine grain and close texture. The 
colors are: dry, 13"f; wet, 15"d ; cones 010 to 1, 7"d ; cone 3, 7"f ; 
cones 5 to 13, Avhiter than 17"f. Finger-nail hardness appears below 
cone 010, and steel hardness develops at cone 5. The fired .structure is 
sound and fine granular, with a slightly rough exterior. The total 
linear shrinkage, plastic basis, at cone 13, is 9.7%. The softening point 
is cone 30-31. The principal uses for this clay are for fire brick, face 
brick and stoneware. 

No. 137 (p. 57). Amador County, lone. M. J. Bacon. "Choc- 
olate." This is a plastic fire clay that is occasionally marketed as a 
sagger clay. It contains 7.0% of +200-mesh sand. The plasticity is 
excellent, the dry .strength is medium, and in the dried condition it 
is medium hard, fine-grained, and close-textured. The colors are : 
dry, 13"f; wet, 9"d ; cone 010, 13"f, fading to yellowish-white at 
cone 02, and continuing to cone 13 without appreciable change. Yel- 
low scumming is especially noticeable. Steel hardness is developed 
at cone 11. The fired structure is sound, fine-granular, and with a 
slightly roughened surface texture. The total linear shrinkage, plastic 
basis, at cone 15 is 16.2%. The softening point is cone 32. 



CLAY RESOURCES AND CERAMIC INDUSTRY 



267 



TABLE No. 12. 
I. White- or Cream- Burning Non-Calcareous Clays. 

A. Opt-n-buruiiig, more than 6'/< appaivnt porosity at cone 15. 

1. Low strength. 



Clay 




No. 


Vc S.W. 


11 


8.4 


12 


10.6 


37 


16.7 


38 


5.6 


62 


7.3 


63 


5.5 + 


64 


5.7 


91 


5.5 


103 


5.0 


128 


8.9 


129 


7.7 


134 


6.8 


159 


13.3 


100 


11.5 


19 


19.9 


194 


14.1 


195 


14.4 


208 


9.2 


209 


12.9 


235 


6.6 


236 


13.3 


237 


6.4 


259 


15.7 


268 


6.0 



% P.w. 


% W.P, 


18.8 


27.2 


21.6 


32.2 


29.7 


46.4 


18.3 


23.9 


20.0 


27.3 


11.85 


17.40 


12.0 


17.7 


10.9 


16.4 


22.5 


27.5 


19.5 


28.7 


14.1 


21.8 


17.3 


24.1 


21.4 


34.7 


30.4 


41.9 


33.3 


53.2 


34.7 


48.8 


29.3 


43.7 


17.7 


26.9 


17.8 


30.7 


31.7 


38.3 


30.6 


43.9 


25.9 


32.3 


19.5 


35.2 


11.9 


17.9 



'.T.S. 


% D.V.S. 


94 


14.5 


49 


17.8 


141 


24.4 


109 


9.6 


94 


12.2 


69 


11.0 


84 


11.2 


194 


11.0 


69 


8.0 


29 


15.2 


33 


14.2 


17- 


12.1 


135 


21.5 


84 


16.5 


171 


25.9 


95 


18.7 


188 


20.5 


+-50 


16.1 


4-90 


22.5 


Low 


9.3 


34 


19.2 


33 


9.8 


120 


26.5 


90 


11.8 



% 



D.L.S. 
4.7 
5.6 
7.5 
3.1 
3.9 
3.5 
3.5 
3.5 
2.6 
4.9 
4.4 
3.9 
6.8 
5.3 
7.9 
5.9 
6.4 
5.1 
7.1 
3.0 
6.0 
3.1 
8.1 
3.8 



Soften- 
ing pt. 
in cone.s 
28-29 
26-27 
34 
33 
34 
33 
33 

30-31 
35 
32 

33-34 
32-33 
32-33 
32-33 
31-32 
32 
33 
32 
32 

30-31 
29-30 
27-28 
34-35 
33 



2. Medium to high strength. 



Clay 
No. 

15 

28 

29 

44 

45 

57 

59 

90 

93 
109 
137 



S.W. 

12.2 
12.1 
8.0 
18.7 
26.9 
23.3 
20.9 
13.8 
14.3 
12.9 
17.0 



% S.W. 
% P.W. 
% W.P. 
D.T.S. 
% D.V.S. 
% D.L.S. 



% P.W. 

13.3 
14.0 
11.8 
13.6 
15.5 
13.3 
24.0 
16.0 
16.9 
13.4 
20.6 



% W\P. 
25.5 
26.1 
19.8 
32.3 
42.4 
36.6 
44.9 
29.8 
31.2 
26.3 
37.6 



D.T.S. 

467 

356 

242 

1375 

1562 

1744 

221 

370 

350 

437 

211 



% 



D.V.S. 
23.4 
22.7 
15.8 
34.8 
49.4 
44.4 
32.6 
24.4 
25.2 
25.0 
28.1 



D.L.S. 

7.3 

7.1 

5.1 
10.5 
14.0 
13.0 

9.9 

7.5 

7.8 

7.7 

8.5 



= Per cent shrinkage water. 

= Per cent pore water. 

= Per cent water of plasticity. 

= Dry transver.se strength, pounds per 

— Drv shrinkage, per cent dry volume. 

= Calculated Ihiear drying shrinkage, per cent dry length. 



Soften- 
ing pt. 
in cones 
30-31 
30 

30-31 
30 
30 
29 

34-35 
31 

30-31 
30-31 
32 



square inch, without sand. 



268 



DIVISION OP MINES AND MINING 



o 



a 
o 
O 

a 



13 



o 


O) 


d 


■a 


Z 


^C 


^ 


S 


UJ 




to 




CO 


CO 


a 


cq 


< 




.a 




1- 


£ 


.a 












o 


a 


B 




j> 


a 

'a 


& 

o 




£ 


ti 




$ 


J2 


^ 






C 

o 


"-< 



o 



o 
O 



o 



o 



o 



o 
o 



o 






> 



fe?'^ 



6?: 






> 



6S^ 



o 
o 









CO CO l>- t^ t^ -<*< 



I ?0 W5 -^ 05 00 O ^H 



I CO* W3 



OS 00 iC OO "^ OS O t^ CO W5 b* >0 *-H t^ O CI C^ »-« lO CO Tj< b- I OS 

■^ i-« C^ ^H 00 O O OO CD OO CO « »C GO lO eC t^ ^ CO fC CO "-H 'OS 
Cq (N OJ CO »-< CO CO C^ t-H CO CO CO i-f CC ^ »0 "^ CO M d »-< f-H > M 



^"•Oiot^r^ooco-^oco 



^CO^^Tt^CflOlC^OOCOIMf-lt^lOl^OsC^fM-^Ot^C^CD 



»-ieo»OcO'-'cOiOcO.-iOS 



C0OcDkCTj<»-t»0Or-'^O*C0SCs^HT-(0>0SO'-i.-«,-( 
»-<<MCO f*3_L ICO _|_ (Mi-ti-H NCO-^CO 



c5.-it--rt<^coooso«-'r^Tt<'^e^c^oco»ooo 



CDiCOiCOOO'^t^iO«i-<cq«00*-(i-tt^iOU5 

ci IC -^J* CO C^ O lO O CD TP o" ■^' -*' CO OS C<I OS* !>.* CO 
*-(r-tCO CO _L I CO J_ C^ ^H »-( 



«-<OOcooor^coost^c^oo 



>C<|iA CD OS M OS C71 CO M* OS h- CO O 



OOcDC^MO»OC^Oi0005MC^cD(M»f3 000iCWiOCO-^t-^C^ C<)C>CDOO»000«-<"*J1I>. 



> 



65'^ 






^: 



OPM 









COr^COiOCDOSCOcO»OTt<W5b-00^<Mt*OOOOOSO*-HOO T-ni5^N*-tC0e000O-^C0 
C^eo»-<COOOOiOO'^Tt*OC^COdOOC^'-HCO»COScOCOOS^* 

T-Hi-ICO <MJ_ ICO _!_ 1-H^H i-> ^^i-HCJi-HM 



OOOf-(W3cDOOOSC<l»OOS 
*-H I »-i CO »-H »-i 



CO*— i-.*<OSOCO»i^COt^OO»OOOCDOOC^-^OOS 



OSOSOO-*(M'-H(M'*t*<MCOi-IOO'^r^t^OOOSCOCO 

OSt'-iOC^eDOCO'-HCSC^OOCOOt^i-HOSiOCO 
<M (M I I Cq I J_i-tr-l -I— ^ 



COO':DOOCO>— tOsOSTj<cDC^ 



iC<» CO 
I CDC^ 



CO00C<l'rJ*.-lTj4CD»fl-r}«iO00 
OSt~^.-ii-HiOOOOQOOSiOcO 



t--C^Ort<OC<l»-<OHMOOOOC^>COOt-^t-^»C»COC-lt-<000 C^OsiOcDOC^b-i-HO»OOs 



0Si-(0s»-ic0i-ii0c0C^CSI»CiCiC0r^Q0OC0d00'-iO00'<^O 



CDOS'^Cq^O(N'-iCO»-lOOC^t^iC^HOS-^OCOI^OSC^(M 
C^ C^ I I C^ I _|_*-( » ,-.^1-1 c^l* 



OCO^HOOSI^C^(MOO^O 
QOI^OOTt*OSOSt^OO'^(>l 



C^COCOOOTficOOCOCOClt-iCOcOtOOcOOSt^l:^ 



^i-iO:iOs»-Hi-Ht^OSCDOi»CCO«:)OSCOOSCO"^t^ 
CDOs'osi— ii-<0»-ii-H'^OOOi-«cOTt<OCDC^CD 



i-Hr~* -rt< 00 i-t O Tt^ iF-t 



CD OS O O »0 1-H 



lOO r^cDOO-^OS 



^ ■<*< as --H 

cdcOi-HO 



c^oc^i-Hioco»cosoosr^c^ooc^osoo(NOdoob»iaTj<o oocococot-Hcooosost*^ 



OiCDi— IC^T- i*-HCOOOOOTj<"^CDU^OcDt>-'^t^Wt)'-<C^JiO'— ' 









6«: 



6§^ 



> 



&?: 



52: 



Class No. 






CO"— 'CDCDCOI^-CO'^r-ii-HCS 
cOcDOOTj"iOC040kOC^CO 

I I " 



iOC^»-t^HCOOOtOi-<C^COOSOSTt<W5COOSiOOC<l 



cot— COcDOSiftC^cOCO'-'COOOCOt^-^cOr^OOCO 
C1*-HC^OC0O'-l»-<<MO»-(O^>Oi-HOC0OC0 

++^ I ^ I • ^ ■ ■ 



H <M O »-» O- 



^cOOMCOOscOWiO^'-H'^i-icOt^OSOOeDO 



^COCOCO(MCOcD»OkOO(Mt— COOSCQCO-^O"* 
^H.-HC<JONOi— i.-(»-iO»-hO'^W3»-hOCO»-h<N 

I 1-^ I" I I" M 



os"^ OS T- < o 00 »o Tt* CO CO r- 1— OS 



»-l C<J CO 00 :D CO M '-« 00 OS lO Tj* CO 

II " + 



t- O CO 00 »-• 00 CO t- t— 00 lO N OS 



t^T-1 t— tJ< CO CO O CO ^ i-H ■'^ O i— c 
1-1 O ,-t A *-H 1-H r-l r-H i-H »-< CO O tJ* 



i/5COCO»OOOCOO«DC<lCO<M(>JOSr-HOOQOC^'-'W300»-<CO»OOS O^-^C^OO'-sJ^OSTt^.-HC^O 

cDo'iflooosi-Hc^oscoocDr— c^ooo'^'-Hr-cDor— -^oci 

COTj*Tl<COCOCOCOC^Tt<rJHCOCO'^-^iOlO»OCOCOiO'^'^-^CO 



(MCOCDCO'^OOCOt— iO»— "C^-^OlOOSOsO^OSOOeOCOC^f— < 

»-H^H»-Hocooi-ii-H.-HO*-HO'i^ioooeoo<-H.-iO'-«oo 

M" I" I I" I I I + 111" + 



COOOeOOCSQOCOiOCO<MOCOOO'^Ot~-COCO<M 



CD^^NCOOCQC^OOiCOOOOOCONtMt^^^O^^ 
NC<l'r-400i-H^i-*'-'»-tC^OCO»0»-<OCOOi-t 

M" I" I I" I II + 



'-< 00 O '-< ^ CD C<l ' 



■<C<l*-HO0»-<t— *OiOOO'-*OS 



coosor-dcDi-HOsosi-Hr^oococoosooscoo 

C<ii-<Q0O00»-<O'r-tCDO«-HO(N»COOC^OO 

II I l + l III L_ 



OOSCDOSCO«3iCOO^O^ 

+ 1 I ++"+ 

QOOO'TfOOOOt— OS(MOOOC*J 



OSO 

I 



'^Ost>-OCO»OCO^H-**t»-*OS 
T-HO'— <C<J«-hOcOOi— <oco 

+1111 I I 






Oi^'^ecooococoo^o 



1-tt^ 00 T-H CC r-t M .-* CO CD W5 CO <M 



000 

I 



OO'^CqCOCOcOO'-HO'* 

+ 1 I M I I 



1— lT-HCCMCDCDC0050C^CQCC»C?OOi050500COeCeOiOCO 



o 

a 



+ 



o 



6? 



La 



II 

00 

6§ 



CLAY RESOURCES AND CERAMIC INDUSTRY 



269 



Absorption and linear shrinkage curves for clays of class 1. 



ft 

i 

-J 



010 08 06 O^ OZ I 3 5 7 S II 13 IS' 



50 

20 

10 

O 

30 

20 

10 

O 

30 

20 

10 

O 













No 


II 
















A 


^ 




























• 






V 




\ 








\ 






.g 




_ _ 




_. 


,. - 


— ■ 


— 


.-, 


\ 












No 


12 
















A 






s, 








































\ 








Ji. 






^4 


._. 




*" 


^ — 


^ 








A 






NO 


37 




















"^ 


— 


X 






























^ 


"^ 


.- 


.-- 


-- 


A 


-- 


■-" 


-- 


■'' 













y> 



010 08 Ob 0^ OZ I 3 5 7 9 II 15 ir 



HEAT TREATneNT IN COIiES. 







'^cu 


ct 




^ 


10 


u,/ 




t,-^ 




2^ 





^ 




§ 


?0 


<o 




^ 




^ 


10 


^ 




!< 


o 


or 




*< 




^ 


20 






^ 




»< 


10 


•« 




t" 





^ 




^1 




t^ 


?.o 


t* 




11- 




^ 


10 


^ 




^ 










A 




— . 


No 


£8 








z^ 


— 


















i?. 










— - 




























— 




_A 






Nc 

s 


.6 


2 




















V 


— 




<^ 


^< 


- ^ 


.- 


... 


— . 


.5 


— 


-- 


•-' 


— . 


..-"■- 






^ 












No. 6;. 














A 
















































-S 
























A 






No 


64 




























' ■ 












,2 








.. 




_ . 


. - 


-- 


■ 



//EAT TREATMENT IN COliES. 



010 08 06 Of CfZ I 3 5 7 S II 13 IS" 



01008 06 Of OZ I 3 5 7 9 II 13 IS' 



I 

ft: 

i 



I 

I 















No. 


91 












20 






























A 




















10 





























s 




















''r ' 










No, 




' ~ ■ 






~ ~ 




20 






A 


~~~ 


























N 


\ 






._ 


.*< 


10 
















, 


■\' 








„-• 




5 








'' 








— ■ 


— 

















1 


A- 






No. 


12 


6 










20 

10 

a 

20 
10 




1 
















— 


■>».» 






























§ 


















.' * 






A 






NO 


12 


9 







































m 


u 


^•y 




.«_ 




.^^ 






_ 


.^ 



1 

a: 

1 

-J 















NO 


13 


4 












* 




A 




















10 

o 

50 
20 
10 






















"^ 








S 
















--• 








A 






No 


15 


9 




















\ 






^ 


























\ 


Nj 


«. 






S. 






_.. 






^ 


''■ 




•-V 





• ~ 










A 






IN a 


16 


D 
























M 




















N 


— 


- 


20 
10 
n 


























... 


^ 


_S. 


_ _ 


. — « 


_ . 




— 


— - 


-»" 


""■" 


... 



//EAT TREATMENT IN CONES. 



270 



DIVISIOX OP MINES AND MINING 



Ahsoriition and linear shrinkage curves for clays of class 1. 



CIO 08 06 Of OZ I 3 5 7 9 II 13 IS" 



^ so 

% 












No 


19 













S 






A 




















^40 


















—■ 




<- 


^ 


^ so 

«40 

1 
** 




















































^ 

i 

^ 

>< 






1 — 












.^_ 


.•' 


._. 


— 












NO 


Id 


4 
















A, 




















-J 
























~" 


























1 


















































1 






^ 


.=u 




_ 


_ 


, _ 


_ _ 


. — . 


un 





1 



010 08 06 Of OZ I 3 5 7 9 II 13 /S" 



SO 
40 












No 


195 
















A 






























■^ 












30 
20 
10 
O 
40 
































































s 






^ . 





-- 


-- 




-• 












N<? 


2C8 










































A. 












— 




- 


20 
10 














- 




















o 








S 










_. 


— - 


^ _ 






























HEPJ TREAmeNT IN CONES. 



HEAT TREATflfNT IN CONES. 



OI0O8 06OfGl I 3 5 7 S II 13 IS" 




010^08 06 Of OZ I 3 5 7 9 II 13 r 



NEAT TREATMENT IN CONES. 




NEAT TREATMENT IN CONES. 



CLAY RESOURCES AND CERAMIC IXDUSTRY 



271 



Absorption and limar shrinkage curves for clays of class 2. 
010 OB Ob Of 01 I J 5 7 9// 



15 /T 






i 

ft: 

s 



5 

I 
I 






so- 
la 



20- 
10 


20 

10 

o 











No 


15 


















A 




-- 


_ 


- 


^ 


















^mi 




S 








.. 


^ ^ 


^ . 


■ •• 










A 




No 


28 














~* 








^N 












*> 






1 








S 








.. 




^^ 


^ ^ 














No 


29 


















A. 
















— 


•«^ 






















s 












KM^ 


w^ 




»•" 






A 




He 


4^? 










- 














^ 




**"" 








s 






















HL 


'f\l 


n 


iEA 


in 


EN 


T'i 


va 


y/i 


rj." 





010 08 06 Of OZ / 3 5 7 S II 15 IS" 

^ 30 
'St 20 

5 10 



^ 10 



5 3C? 

I 













No 45" 
















A 
























^ 














--> 




















s 












__ 
















No57| 
































N 






A_ 




- 




















S 




-. 


^ 


rr 


^>. 


> 










A 




Noisa 


















r 
























s 






K 


^•» 


__ 


-- 


-- 


_S 


— 


— 




* 






\ 


X 



ȣAT TREATMfNTlNCOfiES 



OiODBOb Of Oi I 3 5 7 9 II 15 /r 



i 

k. 

i 

-J 



I 

I 



20 
10 


20 
10 

O 

20^ 

fO 

O 
20 
10 

O 









A 




No 


30 


















































_S 




^. 


_^ 


__ 


__ 


_- 













^ 




No 


93 
























""" 


■^ 




-- 


-^ 










_s 








^ _ 


_- 




— 














No 


10 


9 








— 


1 






A 






— 


— 




■ 






















s 












.. 


^ ^ 










_A_ 




No 


13 


7 




























"-N 




— 


"X 








._ 


JS 


^ « 




-- 


-- 


-' 


** 


— ' 


i"S 



HE/\T TREATMfNT IN C0fiE5. 



272 DIVISION OP MINES AND MINING 

l-B. Dense-Burning, Less Than 6% Apparent Porosity Between Cones 10 and 15. 

3. Generally Refractory, Softening Point Cone 27+. 

No. 70 (p. 169). Riverside County. Eniseo Clay Co. "White 
Plastic." This is a white burning, plastic fireclay, similar in its 
general properties to No. 56 (class 7), a German fire clay, but Avith 
lower dry strength, higher firing shrinkage, higher softening point, and 
whiter color. It contains 6.4:% of +200-mesh sand. It has a strong 
and smooth plasticity, medium low dry strength, and in the dry state it 
is soft and tine-grained. The colors are : dry, 13"f ; wet, 17'"'d ; cones 
010 to 1, ll"f ; above cone 1, nearly white, but with a faint yellowish 
hue. Finger-nail hardness is developed below cone 010, and steel hard- 
ness at cone 02. Deep cracks developed in firing, but the pieces did not 
shatter sufficiently to fall apart. The total linear shrinkage, plastic 
basis, at cone 15 is 17.8%. The softening point is cone 32. The princi- 
pal use of the clay at present is in the manufacture of fire brick, but 
its white color, fineness of grain, and excellent plasticity should make 
it desirable for Faience tile and other uses. 

No. 96 {\).ni). Riverside County. Alberhill. G., McB. & Co. "No. 
10." This is a white-burning clay with excellent smooth plasticity, that 
is extensively used in terra eotta bodies. It contains 1.2% of -+-200- 
mesh sand. The dry strength is medium, and the dried condition is 
medium hard, fine grained, and close textured. The colors are : drv, 
17""d; wet, 17""b ; cones 010 and 08, 13"f; cones 06 to 13, buff 
white. Finger-nail hardness appears below cone 010, and steel hardness 
at cone 1. Absorptions under 10% are obtained at cone 9. The fired 
structure is sound and stony, and the texture is smooth. The total linear 
shrinkage, plastic basis, is 16.0% at cone 15. The softening point is 
cone 32. The best firing range is from cone 1 to above cone 13. 

No. 98 (p 171). Riverside Countv. Alberhill. G., McB. & Co. 
"Bone." See also No. 74, 86, 87, 231, and 232 in class 5 and No. 
103 in class 1. In the natural state, the pisolitic structure of this clay 
is not so well developed as in some of the other bone clays from the 
district. It contains 30.0% of H-200-mesh sand. The plasticity is 
spongy and weak, the dry strength is low, and in the dried condition 
the clay is soft, friable and open-textured. The colors are: dry, 13"f ; 
wet, 17""b; fired, from cone 010 to cone 15, pinkish to yellowish white, 
finishing at a color that is whiter than that of No. 96. Finger-nail 
hardness appears below cone 010, and steel hardness is present at cone 
3. All fired test pieces are hair cracked. The surface texture of the 
fired tests is smooth. The total linear shrinkage, plastic basis, at 
cone 15 is 18.3%. The softening point is cone 35. The calcined clay is 
especially valuable as a fire-brick grog. 

No. 120 (p. 53). Amador County. lone. Jones Butte. Arroyo 
Seco Grant. Leased by the Stockton Fire Brick Co. "Edwin Fire- 
clay." This is one of the best of tlie Tone fireclays. It contains 30.2% 
of -|-200-mesh quartz-mica sand. The plasticity is 'soapy' and moder- 
ately strong, the dry strength is low, and in the dried condition the 
clay is soft, medium-grained, and close-textured. Some fine-grained 
sand is present. The colors are : dry, 17"f ; wet, 17'"d ; cones 010 to 
02, ll"f ; cones 1 to 5, pinkish white; cones 7 to 15, grayi.sh white. 



CLAY RESOtfRCES AND CERAMIC INDUSTRY ^73 

8teel hardnoss is dovelopod at cone '-). Ijoss than 10% absorption 
appears at cone D. All test pieces develop a network of hair cracks 
on firinfr, bnt do not disintejzrate. The total linear shrinkajje, ]>lastic 
basis, at cone 1") is 2:3.0', i. The softeninpr point is cone 34. The calcined 
clay is nsed as grog, and the raw clay as a i)lastic agent, in the manu- 
facture of heavy-duty fire brick. 

No. 144 (p. 18o). Sacramento County. Michigan Bar. Van Vleck 
])roi)erty. This is .similar to No. 143 (class 4), but contains more 
impurities. It contains but 0.6% of H-200-mesh sand. The i)lasticity 
is smofith and strong, the diy strength is medium low, and in the dried 
condition it is medium hard, fine-grained, and close textured. The 
colors are: dry. 17"f ; wet, 17"d ; cones 010 to 06. 13"f ; cones 04 to 1, 
]7"f ; cones 3 to 15 whiter than 19"f. Steel hardness is developed at 
cone 1. Less than 10' « absorption appears at cone 7. The fired struc- 
ture is sound and stony, and the surface texture is smooth. The total 
linear shrinkage, plastic basis, at cone 15 is 20.6%. The best firing 
range is from cone 1 to cone 15. 

No. 273 (p. 163). Riverside County. Alberhill. A. C. & Co. "SH^." 
This clay is classed by California consumers as a ball clay, on account 
of its smooth and strong plasticity, its good bonding .strength, nearly 
white fired colors, and good vitrification range within commercial 
firing limits. It is very similar to the Florida kaolin (see No 59, 
class 2) . The proportion of + 200-mesh sand is 4.6% . The dry strength 
is medium, and in the dried condition it is medium hard, fine-grained, 
and close textured. With 50% of — 20-mesh to H-30-mesh Ottawa 
sand, the bonding strength is 70 lb. per sq. in. There is slight effer- 
vescence in hvdrochloric acid. The colors are: dry, 9"'f; wet, 17"'; 
cones 010 to 06, ll"f ; cones 04 to 5 whiter than ll"f ; cones 7 to 13, 
nearly white. Steel hardness is developed at cone 02, and less than 
10% absorption at cone 0. The fired structure is stony and badly 
shattered at all cone numbers, and the surface texture is smooth. The 
total linear shriidcage. jdastic basis, at cone 15, is 22.4%. The soften- 
ing point is cone 34. It is used in stoneware and whiteware bodies. 

I-C. Dense-Burning, Less Than 6% Apparent Porosity Between Cones 5 and 10. 

4. Generally Piefractory, Softening Point Cone 27+. 
No. 125 (p. 53). Amador County, lone (Carbondale). Arroyo 
Seco Grant. "Gage." This is a white, fine-grained clay, with a 
talcy feel, and smooth, but weak, plasticity. The dry strength is low, 
and in the dried condition it is soft and friable. The colors are dry and 
wet, white with a greenish hue; cones 010 to 9, pinkish white; cones 11 
and 13, nearly white. The plasticity of the clay is not entirely destroyed 
until cone 06 is reached, at which point finger-nail hardness appears. 
Steel hardness develops at cone 5. Less than 10% absorption appears at 
cone 5, and vitrification is complete at cone 11. Slight bloating is notice- 
able at cone 13. From eone 06 to cone 9 the structure is stony, and 
above cone 9 it is glassy. No firing cracks develop. The maximum 
total linear shrinkage, plastic basis, is 19.8%, at cone 11. The softening 
point is cone 30. The best firing range is from cone 5 to cone 11. The 
clay has been used in the manufacture of calcimine, and is suggested 
as a possible ingredient of M'hite tile and stoneware bodies. 

18 — 54979 



274 DIVISION OF MINES AND MINING 

No. 143 (p. 185). Sacramento County. Michi;iran Bar. Property 
of Geo. Cutter. This is a line-frrained, cream-burnino:, plastic clay, 
quite similar to No. 144 (class ;]). It is not now in use, but was used 
many years ago as a stoneware clay. The plasticity is smooth and 
strong, the dry strength is medium, and in the dried condition it is 
medium hard, fine-grained and close-textured. The colors are : dry, 
pinkish white; wet, 21"'f ; cones 010 to 1, pinkish white; cones 3 to 7, 
19''f; cones 9 to 13, 21"'f. Steel hardness is developed at cone 1. 
The fired structure is sound, and stony, and the surface texture is 
smooth. Less than 10% absorption is obtained at cone 5. The maxi- 
mum total linear shrinkage, plastic basis, at cone 11, is 23.2%. The 
softening point is cone 32. When used alone, the clay warps seriously 
both during drying and firing, but will stand much abuse without 
cracking. The best firing range is from cone 1 to cone 11. 

No. 240 (p. 52). Amador County, lone. Core drill sample. Ea.st 
side of Lot 237, Arroyo Seco Grant. This is a cream-burning clay. 
The dry strength is medium, and in the dried condition it is soft, 
friable, fine-grained, and close-textured. The colors are : dry, 15"f ; 
wet, l'"f ; cones 010 to 02, 13"f ; cones 1 to 7, 21'"f; cones 9 to 13, 
23''"'f. Steel hardness is developed at cone 02, and less than 10% 
absorption at cone 1. The fired structure is stony, and one or two 
small cracks are present in each fired test piece. The surface texture 
is smooth. The maximum total linear shrinkage, plastic basis, at cone 
13, is 23.6%. The softening point is cone 32-33. The long vitrifica- 
tion range is especially to be noted. The possible uses are as a refrac- 
tory bond clay in fire brick, terra cotta, faience tile, and stoneware. 
It is the equivalent of the well-known Dosch chiy, Xo. 136 (class 8), 
and has a slightlv better color. 



TABLE No. 14. 

I. White- or Cream-Burning Non-Calcareous Clays. 

B. Dense-burning, less than 6% apparent porosity between cones 10 and 15. 

3. Generally refractory, softening point cone 274-- 



















Soften- 


Clay 
















ing pt. 


No. 


% s.w. 


% P.W. 


% W.P 


D.T.S. 


% D.V.S. 


% 


D.L.S. 


in cones 


70 


12.8 


18.7 


31.5 


171 


21.9 




6.9 


32 


96 


13.7 


15.9 


29.6 


398 


25.0 




1 . 1 


32 


98 


6.5 


20.9 


27.4 


81 


10.8 




3.4 


35 


120 


6.8 


29.6 


36.4 


93 


9.9 




3.1 


34 


144 


17.7 


22.1 


39.8 


165 


29.4 




8.9 


31 


273 


15.6 


21.9 


37.5 


249* 


25.7 




7.9 


34 


* Bonding s 


trength, with 


50% of 


Ottawa sand 


( —20- 


,-1- 30-mesh) 


is 70 lb. 


per sq. 


in. 

















C. Dense-burning, less than 6% apparent porosity between cones 5 and 10. 
4. Generally refractory, softening point cone 274-. 



Glay 
No. % S.W. % P.W. % W.P. 




D.T.S. 


% 


D.V.S. 


% D.L.S. 


Soften- 
ing pt. 
in cones 


125 11.7 31.1 42.8 
143 22.5 21.7 44.2 
240 20.6 22.3 42.9 


26 
245 
335 

ity. 

pounds i)ei 
nt dry vol 

shrinkage, 


16.5 
36.8 
33.7 

• square inch, 
unie. 
per cent dry 


5.3 
11.0 
10.2 

without 
length. 


30 
32 
32-33 


% S.W. =: Per cent shrinkage water 
% P.W. = Per cent pore water. 
% W.P. = Per cent water of plastici 
D.T.S. = Dry transverse strength, 
% D.V.S. =: Drying shrinkage, per ce 
% D.L.S. = Calculated linear drying 


sand. 



CLAY RESOURCES AND CERATSIIC INDUSTRY 



275 



o S ^ 



S c 



+ § + 





s. 


J= 


1 , 


-^ 


-*-- 






>^ 


c 


>. 


,~ 


to 


5 

o 


1 

c 
n 


be 


E. 


bc 




Z 


■^ 




-^ 


CJ 


UJ 


'E 


53 


V. 


L) 

L. 


X 


cd 

< 


3 
CO 




1- 


a 

OS 


o 



•- ^ ^ %^ 



o 



■J3 >. ♦^ ^■ 



o 00-7: 



5 








-■ 


1 


■* 







'-; 


ci — »c o c; -^ 


■ aa-s 




^^i 


O C »C O -^ CI 

CM 5C C-. C IC — 

CO C^4 CO lO CO Tf 






CO 

CJ 

o 


< 


OS <© eo b* t* »« 

t^ O U5»^t^00 






< 


00 to CO ^ CC Oi 

coeor-OM cs 

CM CM CO iO CO CO 


coco -^ 




c 


'■'i 


o ffl r>- Ci t^ ^ 

"-I CM ?0 C: O: OO 
CM — — 


OOiN 




< 


O 5C — -*OD^ 

•-r " -i c: oo cn 

CJ C^» CO -^ C^ CO 


c; CI 00 
cr. 00 — . 

<M coco 




cr. 
a; 

B 

6 


< 


22.8 
18.2 
19.9 

17.8 
20.0 


■^ t* to 

OS — — 




€ 


iCCMCOiCt^Ci 

CO oc CO cr. -^ CM 

CM ^- CO ■-f CM CO 


38 2 
30 8 
10.8 




o 

c 
o 
O 




^ ^ tr-. I - c: :c 
lO «— tc o c; CO 

CM CM CM *- ^^ CM 


O 00 CM 
'*QOCJ 




'^i 


-— Tf 1© CM CM CM 

^ ?C QO '-C »C ^ 
CM « CM '*' CMCO 


cst^co 

--' iC O: 




o 
o 


< 


!£: cr. 'Tf 'ff CM CO 

O CI U.M 1^ — »0 
CM CM CO CI CM CJ 


in ^. t* 

00 -^ CO 




<-^ 


Ci lO CM r^ -r+. Oi 
*— ■ >— CM CO CM CM 


COOOS 

fM COOO 

CO CO CO 




CO 

a; 
o 


'^i 


»-" « o 00 o :o 
O CO O CO »0 r^ 

CO CM ■<*• CO CM C^ 


t^CM to 
CO CI 






CO U5 t^ o: CO 'T 

coco CM ^ O O 
— — — CO CM CM 


OCM 3S 

Tf cooo 

— CM CO 




o 




t^ Tfi-- c: oo O 
-rj. oo o ^^ c:; CM 

CO CM ■* Tt< CM CO 


h- O CM 

000-<i* 
COCO-* 






■-t CM CD »C 00 »C 

O OO O C) -^ CM 
—. 1-4 CM ^ C) 


o -* -* 

^00 -tj 
1— 1 1— ' CO 




o 

c 
o 


..^ 


r^cM »o — in o 

OOO — CC lO « 
COCO-^ TfCOCC 


'^ OO CM 

-^ 'Tf 00 

rp CO CM 




<• 


•— ■ CO >0 *0 CM O 

O iCO «:: 00 C5 


+5.3 
11.0 
23.5 




s 

5 




'^f CM r- CO t^ »o 
CR ^CM !r>r- o 

CO CO -^ f CO -^ 


CM CM CO 

CO 00 Oi 

■^coco 






iC -r -J3 O O -f 
-f -f o :r »c CM 


t* »o b- 

o oo -^ 




o 

3 
c 




O ?0 CMCO SO'* 

oo — CI a= 00 — 

coco "^ TfCO-* 


COO-^ 

r^r^ OS 

-rf CO CO 




..^ 


>o o; CD -<*• »c o 

■»»• CO OS »0 'f o 


'* Cs iC 
O t^ o 




- 

c 


^^^ 


to ^- O CO -* W3 

oo ^ CI u^ r* ^ 

CO CO ■* -^ CO Tf 


coc; o 

«Dt-0 
TfCO -^ 




rf 

^ 


■^ r-co ^ -^ O 
CO CO c; '^ -^ o 


cO^-« 

1 




o 

o 

5 


^:: 


00 1-^ "* 00 '^ o 

t^ ^ ^ CS t^ CM 

CO CO -^ CO CO '<r 


00 C3 
.ceo CO 






CM CI coo -^ CO 
CM^O*CC0»0 


OOCl 

c<ir-ai 

1 






O CO OO O -^ CO 
r^ Ci Ci CI ■* t^ 


icco 




Class 


No... 


cc 


-* 



o. 



6§ 



03 



276 



DIVISION OF MINES AND MINING 



^ 








lO 




<l- 




«1 


j-O 


>«. 




p" 




»^ 


20 


u,,- 




V) 




J 


10 


^ 




tt- 




a- 


u 


<D 




^ 


30 


^ 


20 


or 




?T 




^ 


10 






~j 




w 





V 




t" 


30 


^ 




^ 


20 


«x 




ft- 




g 


10 


t^ 




;$ 






Absorption and linear shrinkage curves for olays of classes 3 and 4. 
0/O^S (?6 ^ ^ / J 5 7 9 // /J /r ^o^g ObO^OZI Z S 7 S II 15 ,S 

^ 30- 

V3 

5 10 













No 


lO 














--. 


_3. 


' — 


N 


























V 






^ 












.s 




.. 


-- 


'- 


-- 


~" 


^ " 


s«5: 


N 












No 


96 
















A 


























■ — ■ 


■— 


\ 


















.s 




.. 


-- 


— 


— 


— 


s-t 


- 


\ 












No 


98 
















A 




- 


^ 


\. 
































N 


\ 


>s- 


^--- 


— 


— 


, 


— 


.S 


-- 


— 


— 


'' 








~- 


J 



HEfiiT TREATtieNT IN CONES. 



^ JO 

^ 10 

»■■ 
§ zo 

I 20 

I 
^ 10 

*« 







A 






No 


120 










^ 








\ 


\ 


























> 


V 










— 


■ - 


s. 


. a.. 


-' 






\ 


^ 




— 


_ 












No 


14 


4 














A 


^ 
































s 


\ 


^ 








^, 


,- 






_s 


_. 


_- 


-' 








^ 


— 


N 












Nc273 










^ 




A 


N 


























V. 


^ 


^ 




c "■ 


^^ 


-- 


— 




— 


.4 


-' 


— 










\ 




>^ 



^£AT rREATMfNT IN CONES. 



010 OS Ob 0^ OZ I 3 5 7 9 II 13 IS" 




/f£AT TREATriENT IN CONES. 



CLAY KESOUKCKS AND CEKAMIC INDUSTRY 277 

II. BUFF-BURNING CLAYS. 
A. Refractory Clays, Softening Point Cone 27 4 

a Oi'EN-BrHNixc. Mori: Than 6'/< Aitahknt Pohositv at Cone 15. 

5. Low Strength. 

Xo. 17 (p. 168). Riverside County. Alberliill C. & C. Co. "Bone." 
A medinm-grained bone clay, witli a deeid(>d, bnt not well-developed 
pisolitic .structure in tlie eruile state. It is used in the manufacture of 
fire brick, high-temperature cement, and to some extent in saggers. 
It contains 29.0 ';f of + 200-mesh grains, has short plasticity, and dries 
rapidlv to a soft, rough textured condition, witli medium low dry 
strength. The colors are: dry, l;}""d; wet, l;i""i; cones 010 to 06, 
17''f ; cone 04, 17'''f ; cones 02 to 5, whiter than 17'"f ; cones 7 to 13, 
17'"f. All test pieces fired above cone 02 were 'crow-footed.' Finger- 
nail hardness is developed below cone 010, and knife hardness appears 
at cone 5. The total linear shrinkage, plastic basis, is 18.5% at cone 15. 
The softening point is cone 34. The best firing range is above cone 5. 
The principal value of this clay is to increase the refractoriness of fire 
brick bodies. 

No. 23 (p. 163). Riverside County. Alberliill C. & C. Co. "West 
Blue." This is one of the more important Alberhill clays, and is widely 
used for light-pink and butf face brick, for sewer pipe, and in fire brick 
to decrease porosity. It contains 11.0% of + 200-mesh sand. The 
plasticity is excellent and the dry strength is medium low. In the dry 
condition the clav has a medium hardness, a fine grain and a close 
texture. The colors are: dry, 17""f ; wet, 21"" ; cones 010 to 04, 5'f ; 
cone 02, ll"f ; cones 1 and 3, 13"f ; cones 5 to 9, ]7"f ; cone 11, 17"d ; 
cones 13 and 15, 15"b, with prominent iron specking. Finger-nail 
hardness is developed at cone 08, and steel hardness at cone 3. The 
maximum total linear firing shrinkage, plastic basis, at cone 13, is 
13.7%. Slight bloating is apparent at cone 15. The softening point 
is cone 29. The best firing range is from cone 1 to cone 13. A pleasing 
mottled texture can be produced by flashing. 

No. 66 {\).\ld). Riverside County. Corona. McKnight pit. Pacific 
Clay Products Co. "Red IMcKnight." This is a bull'-burning clay 
containing a large proportion of non-plastic material. It is suitable 
for face brick manufacture, and as an ingredient of sewer pipe mixes. 
The plasticity is good, though weakened by the presence of 54.4% of 
+ 200-me.sh sand. The dry strength is medium low, and the dry con- 
dition is coarse, open, soft and friable. The colors are : dry, 9" ; wet, 
9"i; cones 010 to 02, 9'b; cone 1, 9'd ; cone 2, ll'd; cone 5, 9'f ; cones 
7 and 9, 9"d; cones 11 and 13, 15"d. Fing<>r-nail hardness develops 
beloAV cone 010, and steel liardness at cone 7. The fired condition is 
sound, open, granular, and medium strong. The total linear shrinkage, 
plastic basis, at cone 13, is 5.6%. The softening point is cone 28. The 
best firing range is above cone 5. 

No. 67 (p. 179). Kivt'i-si<h' Count \-. Corona. IMcKniglit pit. Pacific 
Clay Products Co. "McKniglit Fire Clay." This is a sandy fire clay 
with fair plasticity, medium low dry strength, and a granular, friable, 
dry condition. It contains 64.2% of -)- 200-mesh sand. The colors are : 
dry, 13""d: wet, 13""i; cones 010 to 7, 17"f; cones 9 to 13, nearly 



r: 



278 DIVISION OF MINES AND MINING 

17"'f'. Steel hardness is not developed within the firing range studied, 
up to cone 15. The fired structure and texture is weak, coarse-grained, 
and friable. The total linear shrinkage, plastic basis, at cone 15 is 
7.2%. The soften in<i' ])oint is cone 3.'1. For best results in firebrick 
manufacture, tliis ehiy should Ix* mixed with a more ])lastic fire clay. 

A^o. 77 (p. !()!)). ItiversideCounl.v. Emsco Clay Co. "Pink Mottled." 
This is a buff-burning plastic fire clay that is especially valuable as a 
face-brick clay. The plasticity is smooth and strong, without sticki- 
ness, the dry strength is medium low, and in the dried state it is soft, 
fine-grained and open-textured. The sample contains 11.0% of -f-200- 
mesh sand. The colors are: dry, 7'M; wet, 7"; cones 010 and 08, 5'f ; 
cone 06, 9"f; cone 04, 7"f ; cone 02, i;r'f ; cone 1, 15"f ; cones 8 and 5, 
17"f ; cones 7 to 1, 17'"f ; and cone ]:?, 17"d. A good range of pinks, 
hutl's, and creams is covered, '^fhe fired exteriors, especially above cone 
5, are lightly mottled wi1h iron specks. F'inger-nail hardness is 
developed at cone 010, and steel hardness at cone 5. The fired structure 
is sound, stony and strong. The total linear shrinkage, plastic basis, 
at cone 13, is 13.1%. The softening point is cone 30-31. The best 
firing range is from cone 04 to above cone 13. 

No. 7i (p. 174). Riverside Countv. Alberhill. Los Angeles Brick Co. 
"Bone." See also No. 86, 87, 231 and 232 in the same class, No. 98 in 
class 3, and No. 103 in class 1. In the imtural state, this clay has a 
well developed pisolitic structure, and is hard and brittle. It is used 
in the manufacture of high-grade fii'e brick. The sample contains 
47.6% of -)-200-mesh sand. The plasticity is spongy and weak, the 
dry strength is low, and the dried condition is soft, friable, and open- 
textured. The colors are: dry, ll'd; wet, ll'i; cones 010 and 08, 7'd ; 
cones 06 and 04, 5'f; cones 1 to 5, 9'f; cones 7 to 11, 15'f ; cone 13, 
13'd. Finger-nail hai'dness is developed at cone 08 and steel hardness 
appears at cone 1. All fired test pieces have deep hair cracks, but do 
not disintegrate. The total linear shrinkage, plastic basis, at cone 15 
is 24.6 /^, most of which takes place during firing. The softening point 
is cone 33-34. The clay is especially valuable as a grog in fire brick 
mixtures after calcination at cone 11 to 15. 

No.77 {\^.^1A). Riverside (V)unty. Alberhill. L. A. B. Co. "Gray 
No. 20." This clay is very similar to No. 76 (class 6), but contains 
more silica, is finer-grained, and has a stronger fired structure. It is 
used in face brick and fire brick. It contains 6.6% of -(-200-mesh sand. 
The ])histicity is excellent, the di-y strength is medium low, and the 
dried condition is medium hard, fine-grained, and close-textured. The 
colors are: dry, 17"'f ; wet, 13'"f ; cone 010 to 04, 13"f ; cones 02 to 13, 
17"'f, or sliglitly whiter. Steel hardness api)ears at cone 1. All fired 
structures ai'e sound, and above cone 1 are stony. Al)sori)tion below 
10% is obtained at cone 7. The maximum total linear shrinkage, 
l)lastic basis, at cone 13, is 16.3%. Bloating begins above cone 13. The 
softening point is coiic 30-31. Tlic best (iring range is fi-om cone 1 to 
above cone 13. 

A'o. ;.'Mp. 174). {{ivei'side ("ounty. Alberhill. L. A. B. Co. "Fire- 
clay." This is a buiV-burning, sandy fireclay witJi low ])lastic strength, 
and medium loAv dry strength. It contains 48.4% of -f-200-mesh sand. 
In the dried condition it is friable, coar.se-grained and open-textured. 



CLAY RESOURCES AND CERAMIC INDUSTRY 279 

The colors arc: dry, 17"f ; wet, 18""b; cones 010 to 04, 9"f ; cone 02, 
ll"f ; cone 1, 13"f ; cone 8. 17"f ; cones 5 to 15, 17'"f. Very few black 
specks appear on firing;. Fin<i:er-nail hardness appears below cone 010, 
but steel hardness is not reaclied below cone 15. The fired structure is 
sound, coarse-grained, and open-textured. Tlie total linear slirinkafje, 
plastic basis, at cone 15 is 5.4 /v, nio.st of whicli takes place during 
drying. Tlie softening point is cone )51-;^2. The best firing range is 
above cone 9. 

No. 86 (p. 174). Kivcrsi.h' Couuly. Alberhill. L. A. 15. Co. "No. 
26 Bone." 8ee also No. 74, 87, 2;n and 232, to which this clay is closely 
related. The plasticity is spongy and weak, the dry strengtli is low, 
and the dried condition is soft, friable, and open-textured. The sample 
contains 57.8'^y of +20()-niesli material. The colors are: dry, 17"'d; 
wet, 19"; cones 010 to 5, 9'd ; cones 7 to 11, 15'f; cone 13, 17"d. 
Finger-nail hardness is developed at cone 08, and steel hardness appears 
at coiie 1. Test pieces have hair cracks, when fired above cone 1, but 
do not disintegrate. Tiie total linear shrinkage, plastic basis, at cone 
13, is 12.3%. The softening point is cone 33-34. 

No. 87 (}). 174). Riverside County. Alberhill. L. A. B. Co. "White 
Bone." See also No. 74, 86, 231 and 232. This variety is now design- 
nated "Smooth Bone." and is closely similar to sample No. 232. It 
contains 31.0% of -|-200-mesh material. The plasticity is better than 
that of No. 86, the dry strength is low, and tlie dried condition is soft, 
friable and open. Tlie colors are: dry, 17"f ; wet, 17'"f ; cones 010 to 
06, 7'f ; cones 04 to 13, jniikish and yellowish white. Finger-nail hard- 
ness is developed at cone 08, and steel hardness at cone 3. All fired test 
pieces are lightly hair-cracked. Less than 10% absorption is obtained 
at cone 11. The total linear shrinkage, plastic basis, at cone 15 is 
18.3%. Tlie softening point is cone 34. 

No. 104 (p. 171). Riverside County. Alberhill. G., McB. & Co. 
"No. 5 Sloan." This is a plastic fireclay, high in alumina. The dry 
strengtli is medium low, and the dried condition is soft, medium- 
grained, and open-textured. It contains 32.2% of -f200-mesh sand. 
The colors are: dry, 17"f; wet, 13"d ; cones 010 to 02, 7"b ; cone 1, 
ll"f ; cones 3 to 9, 17''f ; cones 11 and 13, 13'"'f. Numerous small iron 
specks are visible when fired to cone 11 or above. Finger-nail hardness 
appears below cone 010 and steel hardness at cone 1. All fired test 
pieces are lightly hair cracked, and those that were fired at the higher 
temperatures fell apart into Iwo or more pieces. The surface texture 
of the fired i)ieces is smooth. Less than 10% absorption is obtained at 
cone 5. The maximum total linear shrinkage, plastic basis, at cone 13, 
is 23.6 /< . The softening point is cone 34-35. 

No. 126 (p. 52). Amador County. lone. Arroj'o Seco Grant. 
"Baker." This is a ]ilastic fireclay containing 19.6% of -|-200-mesh 
(|uartz and undecomposcd feldspar grains. The plasticity is good, the 
diy strengtli is low. and in the dried condition it is soft, friable and 
mediuiu-grainetl. Tlie colors are: dry, 17"'f ; wet, 17'"d ; cones 010 to 
9, 17"f ; cones 11 and 13, 17"'f. Steel hardness does not appear within 
the firing range studied (cones 010 to 15). Less than 10/^ absorption 
appears at cone 11. All fired test pieces are hair-cracked. The total 



2H0 DIVISION OF MINES AND MINING 

linear shrinkage, plastic l)asis, at cone 15 is 19.5%. The softening 
point is cone 33-34. The best firing range is above cone 9. 

No. 138 (p. 57). Amador County, lone. :\r. .1. IJacon. "Bacon 
Bottom." This clay has a smooth plasticity, medium-low dry strength, 
and in the dried ccnidition it is soft, fine-grained and open-textured. 
It contains 4.2''/^ of -f200-mesh sand. The colors are: di'v, 13"f ; wet, 
]7"f; cone 010, 17"f; fading to ])iiddsh white at cone 02, and to 
yelloAvish Avhite at cone 5; cones 11 to 15, 19"d. Scattered iron specks 
are noticeable at cones 11 to 15. Finger-nail liardness is ap])roximated 
at eone OlU, antl steel hardness is reached at cone 11. The tiretl struc- 
ture is sound and fine-granular, and the fired surface is slightly rough. 
The total linear shrinkage, i)lastic basis, at cone 15 is 18.1%. The 
softening point is cone 29-30. The clay may be used in sanitary 
porcelain bodies to rejilace ])art of the flint and china clay ordinarily 
used. 

No. liO ({). 56). Amado]- County. lone. Arroyo Seco Grant, 
lone Fire Brick Co. "Sand." This is a fire-sand, nearly identical in 
its properties to No. 128 (class 1) with a softening point of cone 32. 
Tt contains \b.()'/v of +200-mesh sand. The fired colors are: cones 
010 to 04, 7"b; cone 02, 7"d; cone 1 to 7, 17" d; cones 9 and 11, 
]9"d; cone 13, 19"f. 

No. 141 (p. 58). Amador County. Jackson Valley. lone. Leased to 
W. S. Dickey Clay IManufacturing Co. This is a high-grade plastic 
fireclay, yet it contains 38.8% of -j--00-mesh matei'ial. The plasticity 
is fair, the dry strength is low, and in the dried condition it is soft, 
medium-grained and open-textured. The colors are: dry l"'"f; 
wet, light gull gray (9)f ; cones 010 to 06, 7"f ; cone 04, 17''f. With 
increasing temperature, yellow replaces pink, and at cones 11 and 13, 
the color approximates 19"f. Steel hardness is not developed within 
the range of temperatures studied (up to cone 15). The fired struc- 
ture is granular, ami hair-ci-acked, and the texture is slightly I'ough. 
The total linear shrinkage, plastic basis, at cone 15, is 14.1/1. The 
softening point is cone 34. This is one of tlie best, fireclays in the 
state, and brick made from this clay, with a calcined grog of the 
same material, are exceptionally good. 

No. 142 (p. 58). Amador County. Jackson Valley, lone. Leased 
to W. S. Dickey Clay Manufacturing Com])any. This is similar to No. 
141, but contains more eolnring and Huxing impurities. There is 35.8% 
of +200-mesh sand. The drv strength is medium low. The colors are: 
dry, 17"f; wet, 15"d; cones 010 to OH. 7"b; cones 04 and 02, 7"d ; 
cone 1, 7"f; cone 3, 9"f ; cone 5, 9'"f ; cone 7, 17'"f; cones 9 to 13, 
]7"d. Steel hardness is developed at cone 3. The fired structure is 
coarse-granidar, and lightly hair-eracketl, with a roughened surface 
texture. The total linear shrinkage, i)lastic basis, at cone 13 is 14.7%. 
The softening point is cone 32-33. Except for lower refractoriness, 
this clay is more workable than No. 141, on account of greatei" strength 
and less fire-cracking. 

No. 191 (p. 133). Najia County Calistoua. Clark and Marsh. 
Average sample. This is similar to No. 190 (class 1), but contains more 
ii*on, and has even less plasticity and fired strength. The colors are : 



CLAY RESOURCES AND CERAMIC INDLSTRV 281 

dry, 17'cl ; wet, ll'b ; cones 010 and 08, 9'b ; eone 06, 9'd ; cones 04 to 5, 
7'd; cone 7, 9'f; cones 1) to 13, 17"'f. The total linear shrinkaue, 
plastic basis, at cone 1:5, is 8.1%. The sot'teninj^- point is cone 30-31. 

Xo. 192 (p. 133). Xapa County. Calisto^'a. Tninicl \w\o\\ Clark 
and ]\rarsh property. This .sample contains a much higher proportion 
of i>lastic matter than No. 190 or 191, but at the same time contains 
sufficient iron to iiivc pale ImlV lii'fd colors. The residue on 200-mesh is 
26.2^;. The i)lasticity is fail', the dry stren«>th is medium low. and 
in the dried condition it is inediuiii-hard, fine-jirained, and open-tex- 
tured. The eoloi-s are: dry. pinkish white, wet, 17"f ; cone 010, 13"f : 
fadin<i- to ])iidvisli white at cone 3, then chanf^ino- to 17"'f at cones 11 
to lo. Steel harilne.ss is not develoiied within the fii'in<i' ranji'e studied, 
up to cone 15. The fired structure is medium-stron<i', tine-granular, 
and at high tiring temperatures is .slightly hair-cracked. The .surface 
texture is slightly i-oughened. A few iron s])ecks are present. The 
total linear shrinkage, i)lastic basis, at cone 15 is 17.1%. The soften- 
ing point is cone 31. 

No. 231 (p. 174). Riverside County. Alberhill. L. A. B. Co. "High 
Alumina Bone." See also Xo. 74, 86, 87, and 232. In the natural 
state this cI-ay has a well-developed pisolitic structure. The plasticity 
is spongy and weak, the dry strength is low, and in the dried con- 
dition it is soft, coarse, and open. The colors are : dry, 9"d ; wet, ll"b ; 
cones 010 and 08, 9'd; cones 06 to 02, 9"f; cones 1 to 5, 17"f; cones 
7 to 13, 19"f. Finger-nail hardness is developed at cone 1, but .steel 
hardness is not iiresent at cone 15. The fired structure is crumbly 
and weak at low firing temperatures, and hair-cracked at higher 
temperatures. The total linear shrinkage, ])lastic basis, at cone 15, 
is 19.6%. The softening i)oint is cone 34-35. 

No. 232 (p. 174). Riverside County. Alberhill. L. A. B. Co. 
"Smooth Bone." See es])ecially No. 87, to which this sample is closely 
siiidlar, except that it is more i)lastic, and less than M)'/( absorj)tion is 
obtained at a lowei- firing tem]ierature, cone 9, instead of at cone 11. 
The total linear shrinkage, ])lastic basis, at cone 15 is 20.6%. The soft- 
ening point is cone 34-35. 

No. 239 (p. 52). Amador County. lone. Core drill sample. Lot 
254. Arroyo Seco ({rant. A sandy clay with fair plasticity and low 
dry strength. It contains 58.0% of +200-mesh sand. In the dried 
condition it is soft, fine-grained, and open-textured. The colors are: 
dry, l""f ; wet, 15"'"b ; cones 1 and 5, 9"'f; coues 9 and 13, 17'"d. 
Steel hardness is not develo|)ed at cone 13. The fired .structure is 
sound and fine-granular. The total linear shrinkage, plastic basis, at 
cone 13, is 3.1%. The softening point is cone 31. The material could 
be mixed with a more pla.stic clay for the manufacture of firebrick. 

No. 244 (p. 52). Amador Connty. lone. Core di-ill hole No. 54, 
Arroyo Seco Grant. This is siniihn- to No. 240 (class 4), but contains 
a larger proportion of fine sand and ferro-magnesian minei'als. The 
plasticity is good, l)ut willi a tendency to stickiness. The dry strength 
is medium low, and in the dried condition it is soft, fine-grained, and 
open-textured. The colors are: dry, pinkish white; wet, l"'"f; cone 
1, 19"f ; cones 5 and 9, 17"d ; cone 13, 17""d. Steel hardness is present 



» 



282 DIVISION OP MINES AND MINING 

at cone 1, and less than 10% absorption appears at cone 5. Blistering 
was noted at cone 13, althougli the softening point is cone 31-32. The 
fired structure is stony, and sound, except for a few small cracks at 
cone 13. The surface texture is suiootli. The maximum total linear 
shrinkage, plastic basis, is 20.8%, at cone 9. It could be used in terra 
cotta and faience tile bodies. 

No. 250 (p. 52). Amador County. lone. Core drill No. 56-3, 
Arroyo Seco Grant. This sample contains but 1.4'/ of -|-2()0-mesh 
sand. The plasticity is good, without stickiness, tlie dry strength is 
medium-low, and in the dried condition it is soft, fine-grained, and 
open-textured. The color.s are: dry, grayish white; wet, carbon gray; 
cone 1, nearly white; cones 5 and 9, 19"f ; cone 13, IT'^d. Steel hard- 
ness and less than 10%) absorption are developed between cone 1 and 
cone 5. In the fired condition the non-plastic grains are well cemented 
in a groundmass of clay. Numerous fine, but deep, cracks appear in 
the fired test pieces. The surface texture is moderately rough. The 
total linear shrinkage, plastic basis, at cone 13, is 14.7%. The softening 
point is cone 31. It is a suitable material for terra cotta, tile, and 
fire brick bodies. 

No. 270 (p. 140). American Refractories Co. "Arc Fire Clay." This 
is a sample of fireclay from which the "Arc" brand of fire brick is 
manufactured. There is slight effervescence in hydrochloric acid. The 
plasticity is excellent, the dry strength is medium low, and in the 
dried condition it is soft, medium-grained, and open-textured. It 
contains 32.0% of -|-200-mesh sand. The colors are: dry, 13"'d; wet, 
13"'b; cones 010 to 06, 9"f; cones 04 and 02, 15"f; cones 1 to 7, 
yellowish white; cones 9 to 13, 19"'f. The surface is slightly mottled 
with iron specks above cone 9. Steel hardness is developed at cone 11. 
The fired structure is sound, and granular, and the surface texture is 
rough. The total linear shrinkage, plastic basis, at cone 13, is 12.8%. 
The softening point is cone 32. 

No. 282 (p. 141). Orange Countv. Santa Ana Canvon. Goat Ranch. 
G., McB. & Co. "Flint Fire Clay." This sample "was prepared by 
wet pebble-mill grinding through 200-mesh, followed by seven days' 
ageing in the plastic state, with frequent pugging. This produced 
good plasticity. The dry strength is medium low, and in the dried 
condition it is medium hard, fine-grained, and close-textured. The 
colors are: dry, 17""f ; wet, 21""d; cones 010 to 04, 13"f ; cones 02 
to 9, nearly white; cones 11 and 13, 17"d. Steel hardness is developed 
at cone 5 and less than 10%) absorption at cone 13. The fired structure 
is fine-granular, and the surface texture is smooth. All test pieces are 
shattered, but most of them remain in one piece. The total linear 
shrinkage, plastic basis, at cone 15 is 18.0%. The softening point is 
cone 33. 

No. 285 (p. 232). Tulare County. Ducor. W. A. Sears deposit. See 
also No. 283-A and B, class 9, and 284, class 10. This is the. most satis- 
factory of the clays that were tested from this ])roperty. The material 
is an impure kaolin, has fair plasticity, and medium-low diy strength. 
In the dry condition it is nu^lium hard, fine-grained, and open-texturetl. 
The colors are : dry, cream white ; wet, 15 b; cones 010 to 1)6, 9"f ; cones 
04 to 5, 17"d; cones 7 and 9, 15"d; cones 11 av^ 13, 13"d; cone 15, 



CLAY RESOUKC'ES AND CEKAAIIC INDUSTKY 



288 



15"d. These are suitable buffs for face brick, but tlie surface is badly 
contaminated with yellow stainin-ir. Tlici-e is no evidence of vitrifica- 
tion up to cone 15, the ui)i)ei- limit studied. The fired structure is 
sound, fine-g:rained, and open-textured, without irreat strength. The 
total linear shrinkage, plastic basis, at cone 15, is 10.8%. The softening 
point is cone 80-:}!. The clay might have uses as a refractory filler 
ill face brick and terra cotta. 



Clay 
Xo. 

17 

23 

66 

67 

71 

74 

77 

79 

8f> 

87 
104 
126 
138 
140 
141 
142 
191 
192 
231 
232 
239 
244 
2.50 
270 
282 
285 



TABLE No. 16. 

II. Buff-Burning Clays. 

A. Refractory clays, softening point cone 27 4-. 

a. Open-burning, more than 6</i apparent porosity at cone 15. 

5. Low strengtli. 



% S.W. 

9.3 

11. S 

7.1 

5.6 

9.6 

5.6 

12.7 

5.9 

6.8 

8.0 

12.4 

13.0 

18.2 

7.8 

5.6 

6.5 

13.9 

15.4 

5.1 

8.1 

4.4 

20.4 

11.0 

11.1 

12.9 

10.7 



% S.W. 
% P.W. 
% W.P. 
D.T.S. 
% D.V.S. 
% D.L.S. 



% P.W. 
20.1 
19.3 
10.3 
9.0 
16.4 
23.2 
18.0 
11.7 
19.9 
14.9 
24.0 
25.4 
25.8 
IS.O 
23.0 
21.3 
30.2 
27.1 
22.8 
21.7 
13.9 
20.1 
17.4 
17.5 
17.0 
44.0 



% W.P. 
29.4 
31.1 
17.4 
14.6 
26.0 
28.8 
30.7 
17.6 
26.7 
28.4 
36.4 
38.4 
44.0 
25.8 
28.6 
27.8 
44.1 
42.5 
27.9 
29.8 
18.3 
40.5 
28.4 
28.6 
29.9 
54.7 



D.T.S. 

136 

161 

185 

142 

131 

97 

m;190 

163 

76 

76 

178 

95 

160 

46 

92 

178 

ISO 

143 

41 

58 

50 

±190 

179 

1.S3 

±14 3 

130 



D.V.S. 
15.8 
20.3 
14.6 
11.7 
17.2 

9.1 
22.5 
11.8 
11.7 
13.5 
19.7 
19.7 
27.9 
13.5 

8.9 
10.7 
18.9 
22.0 

8.1 
13.3 

8.4 
34.1 
19.4 
19.7 
23.5 
11.8 



% 





Soften- 




ing pt. 


D.L.S. 


in cones 


5.1 


34 


6.2 


29 


4.7 


28 


3.7 


33 


5.2 


31 


3.0 


33-34 


7.0 


30-31 


3.8 


31-32 


3.7 


33-34 


4.1 


3 4 


6.2 


35 


6.2 


33-34 


8.4 


29-30 


4.4 


32 


2.9 


34 


3.4 


33 


6.0 


30-31 


6.9 


31 


2.6 


34-35 


4.3 


34-35 


2.8 


31 


10.3 


31-32 


6.1 


31 


6.2 


32 


7.3 


33 


3.8 


30-31 



— i>p,. cent shrinkage water. 

— Per cent pore water. 
= Per cent water of plasticity. 
= Dry transverse strengtli, i)r>uiuls i)er sfiiiare 
r= Drying shrinkage, per cent dry volume. 

= Calculated linear drying shrinkage, per cent dry length. 



inrli, without sand. 



284 



DIVISION OF MINES AND MINING 






^ o 



o 


c 


Z 


c 






III 


3 


-1 


on 


OQ 


if 


< 


3 



e 
o 
O 




:0 CM CO 1 t^ 
--CM -CM ' 


ifi . -r — t^ ^o 

— Cr;0~i- 

CM ■ — — — 


Tf . 'OO "^ o 

^ ' ' 00 CI 00 
CM ' 'CM CM 




' cr, cooo 
or I- CI 


*-* 


0»fr -OS 'i^ 

1^ ^ < O 1 C^l 

co^ .^ lie 


-^ 1 CD -tj« -^ ^ 
iC 'CO »c t^- o 

ICO -*■ CO CO 


CS > ■ IC OC CM 

O > 'OCOCO 
CO • >CO -f -rf 




OCM CD 

' CD CI CI 
' CM CO CM 


CO 

o 
O 




OOCMOOt— CMCM:0-*'--rO'. ^XiCr. ^COcCOCMcDOWS'tJ'Or-' 


CO »— CM CS i-* CM — CM CM CM ^ CO CO CM CM '^ CO CM ^ CO w-" CM CM tJ" 




oocM't-r*^cooourc^OTpr-c^)t^-*'t^'X;c»ocococciiooc^i 


CMCOCOOOCO'rt.OOCM-^C^I«l.yDy3»f500--|-^-^QOO^CO>0 0-fO 
C-tiCM CM-TfCM CMCOt^CO— OICO CMCOf OIOICMCMCM 


o 
o 

O 




c<ir^^ooo-*iooocMa;cMC-ioor^c^icjooooooco 




1 t- OO CM 

'CD Tj«Cl 
1 CI CM -rj* 


Oico»o»oc5»C'^?or^oo04or-cJO-+'cD»oco-^ 

CMC^ICICMCMCO^C^CMCM C'lCOCOCMCM-^COCO^ 




— CO c CT- CM oi o »re o oi 00 •* C71 c^i tf -^ o ~ r^ -«*■ 




■ CT- 1^ CI 

'oi — o 

' ^ CI CM 


CO cr. c^i r- c; i^ uo — >c — »c •* >c in Qo o t^ CO CO cr- 

CO^ •— COC-J O'lCOM'CO^ C^ICO C^ICOCO 


05 

O 

O 




3;OlOCMOOiCClX;.--MI^Cr. 1— CMOU3C:C0CMOCMt^00'^CMOC 


;o-t<-^«3^ — 'fiTGO-^r^cot^ooi^ior^t-oococooot^cniCCM 

CMCMCMCMCMCO'-'CMCMC'l CMCOCOCMCM-fCOCO^CO ^(MCM-^J- 




C^OOf— OOC-rCO — ^GOCOCl — •'^o^cuo-ri-^'—oicococ^jcoicic 


cj; oo CM t- 00 :c »o <M CO 1^ c^ CM -^ »c i-~ c~. QC — S-. r- o CO CO r-- o CT; 

CM— — COCM CM-M-^CO-— ClC^l 01C-)CO_|_COCM — CM- 


- 

c 
O 




CM l^OOT'-^.—OOOQCOClOl^r^QOCOCCCOO'^D 




lOcO o 
' — coco 

> CO CM 'Tj* 

1 ■*— 


00 C3 »c CO CO cr. »o t^ o :o CO -r CO t^ t-^ ic i^ t^ CM »o 

CMCOCMCMCMCO — CMCOCl CMC0C0C^1CM-*C0'^01 


> 


— CNiCCOC:C<JOOOOOaiCD»OCMCMOCiO»OCr. »cco 




'»ocr. oo 


r^-^e-lCDCDOiO-— — •OC0CMC0C0C0C:»0O»0CI 

CM T-H H— ^ CO CI CM O) -^ CO ^ C.-M C^l C-1 CM CO 

-1— -''X 


o 


< 


cocMooi^c^CM-^c^i^»niniooo^'^cocooo»iO*0'^ocrji-^r-co 


COCMCOlOuOf— CMOO — — troOt^OC — r--O000^r^-^"00O — CO- 
COCOC'ICMCM'^C^IC'ICOCO— «CMC0COCOCMTf'CO-"C*lCO-- ^-COC^iTt" 


<■ 


0»0 — OCOCMCOiO'^CMOOOO;«3CMt^i— t^ci-^oooot^t^ocrs 


^-coc-icc-^r-CDO — CMoocscMcMcotOiooouocMcrQocM--t"cr; r— 

CMi— ' » f— <CMC1_J_01CMC0CM— ■ CMCM — 'C'4'?^ ICMCl— '^--h 


CO 

o 

O 


..o^; 

''"-<• 


<aDiC ■O'^ot^ CO— ^cr- CO — -— m:r.ocoooo 




1 kO t^co 

i-rf ^ CJ 
> CO CI -^ 


CD CO r- 00 I-- — CO 0-- 1^ "^ uo -f a. cr. »o — 00 — LO GO 

COCOCMC^lCM^ClCMCOCOCO-^CO^COCO'^'t'^Ol 




OCM'<**t^CMOOCOI^CD--*'«*t^OO'^CMOOO — CMCD 




'Osor* 

' o OS r^ 


t-O — -S-CMinOlOCOOCM — 0^0-rfCO»0 — CO 
— -- — CM— |— CMC^)^— =», CMC-1 — CMC^l 


c 


of^ 

""-H 


oiiouoco- oo>o-rOi — O3ico— •r^cM»C'cr^ocMOoo-n*oo 


00 -T Ci CO GO ^ CO O :r-. O QO CO O r: CO O Cr. C^l -JD T," ic cc o ic 3; — 
COCOClCMCM-n'CMCOCOrOCO'^-^'C^-^'r-^-r'^J'COCOCMCOCOCM''^ 

++ 


, ^'^ 

^ 


— CO»C»COOCMCOCMCO>— «Ot^OcD»— 'I~*COai»— — ^t-t^'— tCOiO 

COCOOCOOCOCO — — OClCOt^ — OCMCMCIOO — — c:cooi*or^ 


o 
a. 

o 

O 




ococor-CMO-ri-cococoy^oocoOookOcoo 'CO 

OCOOOOOOt^ — 310 0-. 0»C — OCOCMC:-Tf iOO 
':J^COCMCv|CO-^COCM-:t"CO'rrTr-rf-^-^T*>-rt'Tt< .CO 




• »CCM O 

• 00 C 1 CI 

■ coco -^ 


< 


^C'l — cDc0CMi0»CU0Ot-^— C^l'^OCOCO'1' -OS 




1 O CM CD 
' iC CI >c 


CM CD OCO t^ QOO — CI — CO O irt O O; O CM O ' !£) 


o 
o 
c 




lOiC — I^CMCO^X>C-lO0=r. COCD-tf-TfiOiOl^O^^ 

CM^CJ:cr>-:fCr. COCTO — — CO — o^cocrcocD — 
rJ"COC^lC'lCO'^CO<MTj'T)'-^-^-:frt"-+i"^Tf'^»C-^ 




icortr^ 

''oO-rt- — 

iCO CO -rt* 




iC~. — oiCTrcMi^-r**ai»0'rr't--c^3tDOcortii:^co 




i»0 cr- CO 


00 — OCOCMCOkO— 'OiOO'^00'«rOOOCi — oococo 


o 

5 
O 




h-cOr-iCOCD-«:J*OaOCMr^OOiiO(MCMOCOCCCOcO 




' — 00 00 

1 Ci -rt* CM 
iCOCO -^ 


CMOOCr. OicOCr. t^Cl05^-CMCD — O'^COCJiTfOiO 
"rt"COO)C-'ICO'*COCMCO'rfT}*"rf'rfTfTf"^-^'Tj-"^'^ 


L-;j 


C0t^C0t^C0C-lTf00O00t^CM3:OC0C0'rfOC0CM 




'CM T}< CI 

iCOOiC-- 


OO—^OCMO-ICOCO- O00^00TfC2000i'--t--C0C0 


CO 

o 
a; 
C 

o 

O 


'^^ 


OCM — C^IOOOIOO — 0000OC^^C:!0000C0CM^--* 




. CD 'CI 
• CO "^ 


CMQ0ClCX^Q0U0Q005O— t^— Cl-^CMCS-'J'OOO 
TfCOCMCMCOTfCOCMCO'*Tt'Tf-^CO'*-?T"<t''^^-* 




mr-t^t^OsCOOOOOO- 00(^0 — CCCMt-C-JOO 




■ — 'CO 

'CO -tn 


»C— OCMO — CMCMCnOC^r-Tj^OOOOO- CDCM — 


o 
o 

c 


^'i 


CMOOTfOClCMOiC^tuOcOOcOCOii^iCOO — »ccr; 

^OOOOOOfOOCDOOO; — CMr^OO^tCMOO-t-OOO 
•«#COC^lC^4COM-C0 01CO-^-rf-n*-^'^'*-r^^-J"* 




' c; a: CM 

> CI "Tf "rt< 
' CO CO tT 




CD — OOOCOOOO — COiOCOOwOOC-lCIClCCl 




ioot^ -* 
' — oo»o 


r-oo — ocico(Nr^oooO'**'Tj«or>-c»^»oooo 

+ 1-1 




1^ CO CO t^ — 'ff 1^ 

— CM CO CD r^ r^ r^ 


3;cor-^;ococ;— oj — CM — c^ic^. 

l-^ 00 OO O C^l CO ■^ -^ «T O". C"- CO CT CO 


-*• :r: o CI »C 

— ic r - 00 CO 

CM Ol CM CI CI 




Class 


No 


lo 











+ 



o 



o 

o 



+ 



o 



o 



— — iZ in 



Ct, 



6? 



> 



PLAY RESOURCES AND CERAMIC INDUSTRY 



285 



AlisiirpLii'ii ;i"il liiuar sluinkaKi' cuims I'lH- rlavs n( class 5. 



•-0 

5 



Or. 
Or: 

i 

-J 



010 08 06 Cf 02 J 3 5 7 S II 15 /T 

20 
10 

O 
SO 
10 


10 



10 


o 

° /iEfi T TRlfMNEN T IN COnES. 









A 


— \ 


Noi 


17 










1 








<. 


— . 


















V 


\ 


— 




fC< 


X 


.. 


._ 





_s 


-- 














N 








< 




Nc 


.23 






























^ 




\ 




*> 


,^ 




— —j 




s 


.. 




— • 


.-• 


-- 







^v 




-J 




A 


h-H 


H<x 


66 






- 


















r— 




~^ 








s 






i»- 




■ ■■ 














A 




Uot 


6i 










^ 














1 




~~ 


— ~ 










S 








.. 


. _ 


_ _ 





-- 








A* 


-^ 


ho 


71 






- 


S^ 










s. 


.- 


-- 


.- 


-- 


-- 



ft: 

i 

-J 



i 
I 
I 



CIO OBOb m OZ I 3 5 7 9 II 13 /f 









A_ 


*^^ 




No 74 












20 
20 

to 



20 
10 








^^^ 


\ 




^ 










r' 
















..- 


^ 




/" 


-- 


-- 


_S_ 


-- 


K*^ 














\ 






■A 






Nc77 


















'v 


\ 




















A 


^ 


-- 


-- 


*" 


>s 


_-- 




- 


X 













^ 





___ 


I^l0| 


[79 












10 













^■~ 






■ — ■ 


*^ 






S 
























A 






No 86 












ZO 










■"■ 














N 


— 






— 




IQ 

n 


.j^ 


-- 


_s 


— 


— 


— 


^<** 













//EAT TRErn'MENJ INCOMES. 



010 08 0b Of OZ I 3 5 7 9 II 15 /S' 



010 08 06 Of OZ I 3 5 7 9 II 15 /T 




//EAT TREAinENT IN CONES. 




HEAT TREATnENT IN CONES. 



286 



DIVISION OP MINES AND MINING 



Absorption and linear shrinkage curves for clays of class 5. 



010 OB 0(> (H OZ I 3 5 7 9 // /J /T 



5 /o 



I 




•~J 




frS 





•» 




^" 


30 


S' 




<ri 




f: 


20 


Q 




u- 




^ 


10 


<t\ 




;§ 







Nol8Z 



010 08 Ok Of OZ / J 5 7 9 // /5 /T 



I 20 

% 
^ 10 

I" 

% 
■^ 

^^ 

I 

I 
^ 10 



^EAT TREfirrnENT IN CONES. 



•>> 




A 




■^ 


No 232 








! 






'*v. 


1 












N 


— , 


»-< 


-' 


— . 




-- 


.- 


-- 


.S_ 


-- 


-- 


-' 






'V 


-^ 




^ 












No 


23 


9 










































S 






















No,24W 




















^ 




.-+-1 


















's 


^ 








>■ 














NaZSO 




















k 


s 






















's' 








^ 


•"'^ 


r 



HEfiJ TREfiTilENT IN CONES 



01008 0b OfOZI J S 7 ^ II lis IS- 



I 

ft: 

-J 



5? 

I 

I 



50 
20 
/O 



zo 

10 


^ 

30 

20 

10 















No 


.27 















— 




A 


■"^ 








































^ 


s^ 








.?. 




*** 


-•- 


-- 


,.. 


— 


.— 


-^ 








A 




No 


28 


2 
















""* 


■^ 












N» 








». 


... 


... 


S 


-- 


-- 


... 


... 


... 


... 


I^s 


\ 












No 


28 


5 










"^ 


^ 


A^ 


— . 












^ 


^ 


























































.^ 


— 


^ 


J. 


— 












__ 


__ 

















//-^/)7 TRE.'MnENT IN CONES. 



CLAY RESOURCES AND CERAMIC INDUSTRY 287 

(i. .Medium to lli.uli Strength. 

\o.!J {\).\ii:i). Riverside County. Alherlnll. (". (fc ('. ("o. " Hill liluo." 
See No. 271, and 274 in class 7, and 272 in tliis class, Avhicli are better 
samples of the material that will be available in the future. This is a 
smootli, fine p-rained, bulf'-burniii<i: refractory clay with prood plasticity, 
and medium higli dry strength. It contains 4.S'/(> of +200-mesh sand. 
It is used in art tile, stoneware, terra cotta, and sagger bodies, and 
represents one of the most widely used of the Alberhill clays. The 
colors are pinkish and buffisii white, approximating Kidgway's "f" 
tone. Finger-nail hardness is developed below cone 010, and steel 
hardness at cone 02. Vitrification is well advanced at cone 13. The 
maximum total linear shrinkage, plastic basis, is 13.3% at cone 13. 
lUoating is apparent at cone 15. The softening point is cone 29. The 
best firing range is from cone 04 to cone 13, and hard, strong bodies 
with absorptions below 10% are obtained above cone 3. 

No.Uiii.lG'^). Riverside County. Alberhill C. & C. Co. "A-Clay." 
This is a pink and buff-burning plastic clay used in the manufacture of 
face brick. It contains 19.27o of -|-200-mesh sand, develops excellent 
plasticity, has a good dry structure, and nu'dium high dry strength. 
The colors are: dry, 17'"d; wet 17"'b; cone 010, 9'f ; cones 08 to 04, 
5'f ; cone 02, ll"f; cones 1 to 5, 13"f ; cones 7 to 9, 17"f ; cone 11, 17"f ; 
cone 13, 15"d. Finger-nail hardness is developed below cone 010, and 
steel hardness at cone 3. The total linear shrinkage, plastic basis, is 
11.1% at cone 13. The softening point is cone 31. The best firing 
range is from cone 3 to cone 13 or above. A wide range of butf and 
pink colors can be secured in the normal kiln run. 

No. 27 (p. 163). Riverside County. Alberhill C. & C. Co. "No. 10." 
This is a pale buff-burning clay with excellent smooth plasticity, 
medium-high dry strength, and a medium-hard, fine-grained, close- 
textured dry condition. It contains 2.6% of -j- 200-mesh sand. It is 
used in sagger, art tile and dry-pressed brick mixtures, and was for- 
merly used in architectural terra cotta. The colors are: dry, 13'"f ; 
wet, 13'"k; cones 010 to 1, 15"f ; cone 3, 17"'f ; beyond cone 3, to cone 
15, increasing yellow, decreasing i)ink, with scattered fine brownish 
and black specks. Finger-nail hardness appears below cone 010, and 
steel hardness at cone 3. The total linear shrinkage, plastic basis, at 
cone 13 is 16.1%. Bloating is apparent at cone 15. The softening point 
is cone 30-31. The best firing range is from cone 3 to cone 13. The 
smooth texture, light colors, and excellent plastic, drying and firing 
qualities of this clay make it especially desirable for many purposes. 

No. 33 (p. 205). San Diego County. Cardiff. Vitrified Products 
Co. See also No. 34. This is a light-colored fireclay, of Pleistocene ( ">.) 
age, containing 41.0% of -f- 200-mesh sand. It is used for fire-brick and 
for buff or cream face brick. It has weak plasticity without stickiness, 
medium-high dry strength, and in the dry state it is hard, with a 
granular structure. The colors are : dry and wet, yellowish white ; 
cones 010 and 08, 13'"f ; cone 06, 17'''d; cones 04 and 02, 15"d; cones 
1 to 13, 17"d. These colors, coupled with a granular texture, make 
pleasing effects for buff and cream face brick. Finger-nail hardness 
appears below cone 010 and the hardness at cone 13 is slightly less than 
steel. The total linear shrinkage, plastic basis, at cone 13, is 8.6%. 



288 DIVISION OF MINES AND MINING 

The softeninj? point is cone 30. The best firing range is IVom cone 1 to 
fibove cone lo. 

N(/. .'>'/ (]). 'JO;")). S;in Dic^o Coiinly. CnrdiiT. N'ili'ificd I'l-odncts 
Co. See also No. 'A'-i. This chiy is from another part of tlie same bed 
from which No. 33 was taken, and is similar to it in every respect, but 
has less sand, more iron, strongei- plasticity, and slightly greater 
shrinkage. It contains 31.0% of -|-200-mesh sand. The colors are: 
dry, y"'f ; wet, 9'"d; cones 010 to 04, 7"f ; cone 02, l"d; cones 1 to 7, 
]5"d; cones 9 and 11, 17"d ; cone 13, 17"b. Steel hardness appears 
at cone 13. The total linear shrinkage, plastic basis, at cone 15, is 11.5%. 
The softening point is cone 31. The best firing range is from cone 1 to 
cone 15. 

No. 53 (j). 195). San Bernardino County. Hicks. Millet and 
Kennedy. This is a buff-burning, plastic fireclay o" Tertiary age 
from an undevelojied deposit. The plasticity is good, the dry strength 
is medium high, and the dry condition is hard and close grained, with 
a heterogeneous texture caused by the presence of non-plastic grains 
of a different color than the clay portion. The sample contains 10.4% 
of -)- 200-mesh material. The colors are : dry, nearly white ; wet, 19"f ; 
cones 010 to 1, ll"f ; cones 3 to 9, 17'"d; cones 11 and 13, 17'"f, 
mottled, with slag spots. Finger-nail hardness is obtained below cone 
010, and steel hardness develops at cone 02. The fired structure is 
sound throughout, and vitrification is well advanced, but not complete, 
at cone 15. The maximum total linear shrinkage, plastic basis, at cone 
]3, is 20.1 *;(. The softening point is cone 30. The best firing range is 
from cone 04 to cone 13. The clay is suitable for the manufacture of 
pink and buff face brick, and as a bond clay in fire brick. It is possible 
that material of improved qualitj' can be found if the deposit is 
developed. 

No.76 {\).\1^). Riverside County. Alberhill. L. A. B. Co. "Gray 
No. 23." See No. 77, class 5. This is a plastic buff-burning fireclay 
that is particularly useful in sagger and pottery mixes. The clay con- 
tains 2.2% of + 200-mesh sand, the ])lasticity is excellent, the dry 
strength is medium, and tJie dried condition is medium hard, fine- 
grained, and close-textured. The colors are: dry, 17'"f; Avet, 17'"d; 
cones 010 and 08, 7'f; cones 06 and 04, 9'f ; cone 02, 13"f ; cones 1 to 13, 
17''"f, or slightly whiter. The fired colors are good buffs and creams 
for face brick, faience tile, and similar ])roducts. Finger-nail hard- 
ness is developed below cone 010, and steel hardness at cone 1. The 
fired structure is sound and stony, and smooth textures are obtained. 
Absorptions below 10% are obtained at cone 9. The maximum total 
linear shrinkage, plastic basis, is 15. 6*;;, at cone 11. The softening 
point is cone 29. The best firing range is from cone 1 to cone 13. 

No. 78 (p. 174). Riverside County. Alberhill. L. A. B. Co. 

'No. 10." This is a dark colored, butt'-burning, plastic fireclay, con- 
taining carbonaceous matter. It is used for fire brick and face brick. 
The sample contains 16.2% of + 200-mesh sand. The plasticity is 
excellent, the dry strength is medium-high, and the dried condition is 
medium-hard, medium fine-grained and close-textured. The colors are : 
dry, 13'"'d; wet, 13""i ; cones 010 to 04, 9'f; cone 02, 13''f; cones 1 
to 13, between 17"'f and 21"'f, although slightly whiter at some cone 



<<i 



CLAY RESOURCES AND CERAMIC INDUSTRY 289 

luiiiibcrs. Scattered yellowish speeks apjx'ar at low firin<i' temperatures, 
which darken and become more ijrominent at hij>li temperatures. 
P'infrer-nail haiduess appears below cone 010, and steel hardness at 
cone 1. Absoi-ptions above lO'y are found above cone 8. The fired 
strneture is sound and above cone 02 is stony. The total linear firing 
slii-iidcage, phistic basis, at cone 13, is IT.l^r. Slight bloating- w^as 
noted at cone L'v The softening i)oint is cone 29. The best firing 
range is from eone 1 to cone 13. The plasticity, dry and fired strength, 
and wide vitrification range at commercially attainable temperatures 
are the most valuable properties of this clay. 

Xa. 81 (]). 174). Riverside County. Alberhill. L. A. li. Co. 
"No. 25." This is a i)lastic fireclay, similar to No. 76, but with more 
coloring matter, and a higher jn-oportion of clay substance. It is used 
for face brick and fire brick. It contains oidy 1.8'/^ of +200-mesh sand, 
the plasticity is smooth and strong, the dry strength is medium high, 
and the drv condition is medium soft, fine-grained, and close-textured. 
The colors ^are: dry, 17'"f; Avet, 17'"b ; cones 010 to 1, ll'd; cones 3 
and 5, ll'f ; cones 7 to 11, 17'"f ; cone 13, 17"f. These are suitable 
butfs and tans for face-brick manufacture. Finger-nail hardness 
appears below cone 010, and steel hardness at cone 1. Absorptions 
below 10% are obtained at cone 7 and above. The total linear shrink- 
age, ])lastic basis, at cone 13, is 15.8% . The softening j^oint is cone 28. 
The best firing range is above cone 1. 

No. 84 (p. 174). Riverside County. Alberhill. L. A. B. Co. "Main 
Pit Fireclay." This is a i)lastic fireclav, similar to the "Main Tunnel" 
clavs mined bv the Alberhill C. & Co. Co. and by G., McB. & Co., 
see samples No. 15, 29, 90, and 93 in class 2, and No. 13 and 229 in 
class 7. It contains 11.0% of +200-mesli sand, the ])lasticity is smooth 
and strong, the dry strength is medium, and the dry condition is soft, 
fine-grained, and close-textured. The colors are: dry, 17"'f; Avet, 
]7"'d; cones 010 to 13, 9'f to 17'f. Green staining is pronounced. 
Finger-nail hardness develops below cone 010, and steel hardness at 
cone 3. Less than 10% absor])tion is obtained at cone 5. Vitrification 
is well advanced at cone 13. With the exception of a few cracks that 
resulted from the rapid fii'ing schedule used, the fired test jiieces are 
sound. The total linear shrinkage, plastic basis, at cone 13 is 12.2%. 
The softening point is cone 28. The best firing range is above eone 3. 
The clay may be used in fii'c hiick, face brick, faience tile, stoneware, 
and pottery mixes. The color is not white enough for whiteware bodiea 

No. 92 (p. 171). Riverside County. Alberhill. G., McB. & Co. 
"Yellow Main Tunnel Clay." This is a i)lastic, butf-burning clay 
that can be used in fire brick ami face brick. It contains 16.8% of 
+200-mesh sand. The ])lasticity is smooth and strong, the dry strength 
is medium-high, and in the dried state it is medium hard, fine-grained, 
and close-textured. The colors are: dry, 17"d; wet, 17"; cones 010 
to 02, 7'd; cones 1 to 7, 7'f; cones 9 to V.\, 17"d. Scattered slag 
spots appear above cone 9. Finger-nail hardness appears below 
cone 010, and steel hardness at cone 1. Absorptions under 10% 
are found at cone 11. The fired structure is sound, and at high tem- 
])eratures, is stony. The total linear shrinkage, plastic basis, at cone 
13, is 13.6%c. The softening point is cone 28. 

19 — 54970 



290 DIVISION OF MINES AND MINING 

No. 97 (p. 171). Riverside Connty. Alberhill. G., Me.B. & Co. 
"Smooth Bunker." Thi.s is a hufir-bnrniiif!: terra eotta clay with excel- 
lent plasticity and medium higrli dry strengrth. Tlu^re is slight ett'er- 
vescence in hydrochloric acid. In tlie dried condition it is soft, fine- 
grained, and close-textured. Tt conlains 15.6% of +200-mesli sand. 
The colors are: drv, 13""d; wet, 17""d; fired, from cone 010 to cone 
13, 13"f to 17'"f. ^ The color at cone 13 is deeper than in No. 96 (class 
3), and a few iron specks appear which are not present in No. 96. 
Finger-nail hardness appears below cone 010, and steel hardness at 
cone 02. The fired structure is sound and stony, and the texture is 
.^lightly rough. Absorptions under lO.O'/r are obtained at cone 11. The 
total linear shrinkage, pla.stic basis, at cone 13, is 11.4%. The soften- 
ing point is cone 31. The best firing range is from cone 1 to cone 13. 

No. 102 (p. 171). Riverside County. Alberhill. G., McB. & Co. 
"Sloan Sand." This is a sandy fireclay witli fair plasticity, medium 
dry strength, and a medium-hard, medium-grained, open-textured dried 
condition. It contains 30.6% of -}-200-mesli sand. The colors are : 
dry, 17"f ; wet, 15"; cones 010 to 02, 9"b; cone 1, 9"d; cones 3 to 11, 
13"d; cone 13, 17"d. At cones 11 and 13, scattering gray and brown 
specks appear. Finger-nail hardness appears below cone 010, and steel 
hardness develops at cone 3. The fired condition is sound, granular, 
and rough-textured. The total linear shrinkage, plastic basis, at cone 
13, is 9.7%. The softening point is cone 29. The clay is suitable for 
the manufacture of face brick, and as an ingredient in low-grade fire- 
brick mixes. 

No. 108 {p. \1^). Riverside County. Alberhill. Pacific Clay Products 
Co. "Tapper Douglas." Tliis is a deep buflf-burning sewer-pipe clay 
with good plasticity, high dry -strength, and in the dried condition it 
has finger-nail hardness, and a fine grained and close texture. It con- 
tains 5.8% of -)-200-mesh sand. The colors are: drv, 17"f; wet, 
13"d; cones 010 to 02, ll'd; cone 1, 15'd; cones 3 to 13^, 15"d. Steel 
hardness is developed at cone 1. Less than \Q% absorption is developed 
at cone 3. Vitrification is complete at cone 11, after which bloating 
begins. The fired structure is sound and stony. The maximum total 
linear shrinkage, plastic l)a.sis, is 20.0%, at cone 11. The softening 
point is cone 27-28. 

No. 130 (p. 62). Amador County. Toiu\ "Newman Carbonaceous 
Sand." This is a fire sand high in carbonaceous matter for which no 
uses have been found. Some iron compounds are present which are 
partly soluble in the mixing water, and cause discoloration by efflor- 
escence. The residue on 200-mesh is 16.0%. More clay is present than 
in No. 129 (class 1), resulting in better plasticity, and medium dry 
strength. The interior colors are: drv, 15'""b; wet, 15""m; cones 
010 to 1, 15"b; cones 3 to 5, 13"b; cones 7 and 9, 13"b. The efflor- 
escence has a 5'i color from cone 010 to cone 1. Steel hardness is 
approximated at cone 3. Tlie fired structure is sound, fine-grained, and 
open textured. Light hair-cracks appear on the surface of test pieces 
fired above cone 3. The total linear shrinkage, plastic basis, at cone 9, 
is 11.6%. The softening point is cone 27. 

No. 139 (p. 52). Amador County. lone. M. J. Bacon. "Bacon 
Blue." This is a fine-grained, cream-burning, plastic clay that is 



CLAY RESOURCES AXD (■EKA>tIi' IXDUSTRY 291 

suitable for stoneware maiinfactiire. It contains 1.4% of -f-200-mesh 
sand. The plasticity is very grood, the dry strenprth is niedinni Ioav, and 
\u the drii^l coiidilion il is niediiiin-hard. fiiic-^nviined, and open- 
textured. The c<)h)rs are: dry, l:5""f; wet, 17""f; cone 010, 17"f, 
changiuf? to pinkish white at cone 02, then to cream-white up to cone 
9; cones 11 and 13, 19"d. Fiufrer-iuiil hardness is approximated at 
cone 010, and steel liardness develops at cone 7. Less than 10% 
ab.sorption is developed at cone 9. The fired structure is sound and 
stony, and the surface texture is smooth. The total linear shrinka<?e, 
plastic basis, at cone 13, is 17.7%. Bloating is pronounced at cone 15. 
The softening point is eone 29-30. TIk^ liest firing range is from cone 
5 to cone 11. 

Xo. 145 (p. 156). Placer County. Lincoln. Liiu-oln ("lay Products 
Co. "Xo. 0." This variety of the Lincoln clay contains a large i)ro- 
portion of sand, and enough iron to give buff and pink colors on firing. 
It effervesces slightly in hydrochloric acid. The ])lastieity is good, the 
dry strength is medium-high, and in the dried coiulition, it is medium 
soft, medium-grained, and open-textured. The colors are: dry, 17"f; 
wet, 17"d; cones 010 to 02, ll'f ; cones 1 to 5, 13'f ; cones 7 to 13, 17'f. 
Steel hardness is develoj)ed at cone 1. Less than 10% absorption 
appears at cone 9. The fired structure is sound, and consists of sand 
particles imbedded in a clay ground mass. The fired surface texture 
is rough, and at high firing temperatures, the surface is mottled. The 
maxinuim total linear shrinkage, plastic basis is 17.7% at cone 13. 
Sligiit bloating develops at cone 15. The softening point is cone 30-31. 
The best firing range is from cone 1 to cone 13. The clay is used in 
face brick mixes, and could be used for the cheaper grades of fire brick, 
and in terra cotta. 

No. 150 (p. 156). Placer County. Lincoln. Lincoln Clay Products 
Co. "Xo. 10." For all practical purposes this clay is identical to Xo. 
149 (class 7) although the dry strength is 25% higher, and the porosi- 
ties are somewhat higher. Xo blistering can be detected when fired to 
cone 13, but bloating is apparent at cone 15. The total linear shrink- 
age, plastic basis, at cone 13, is 20.6%. The softening point is cone 32. 

No. 197 (p. 227). Sonoma County. Two miles east of Beltane. 
This clay, from an undeveloped deposit, has good plasticity, but with 
a tendency to sponginess, medium-high dry strength, and in the dried 
condition it has finger-nail hardness, is fine-grained, and open-textured. 
A tendency to crack during drying was noted. The colors are: dry, 
yellowish white; wet, 19"f (yeilow-bulf) ; cones 06 and 02, 17"f ; cone 
1, 17"b ; cone 3, 17"d. The fired colors are too yellowish for good face- 
brick effects. Steel hardness was not develoi)ed at cone 3, which was 
the highest temperature studied. The fired structure is sound. The 
total linear shrinkage, plastic basis, at cone 3, is 12.3%. The softening 
point is cone 27-28. More data are needed before a prediction of pos- 
sible uses can be made, but the clay seems Avorthy of further investiga- 
tion. 

No. 257 (p. 52). xVmador Co\mty. lone. Core drill hole Xo. 62, 
Arroyo Seco Grant. This is one of the best of the core-drill samples 
that were tested. The plasticity is good, with a tendency to stickiness, 
the dry strength is medium high, and in the dried condition it is medium- 



292 DIVISION OP MINES AND MINING 

hard, fine-grained, and close-textured. There is slig^ht effervescence in 
liydrochlorie acid. The colors are: dry, 17""d; wet, 13""k; cone 1, 
nearly white; cones ") and J), buff-wliite; cone 13, 17"f. Steel hardness 
is developed l)etween cone 1 and cone 5, and less tlian 10% 
absorption between cones 9 and 13. The fired structure is .sound and 
stony, and the surface texture is smooth. The total linear shrinkage, 
plastic basis, at cone 13, is 18.7 /f . The softening ])()int is cone 31-32. 
Tins clay is suitable as a refractory bond clay in fire brick, terra 
cotta, and tile, and might be u.sed in stoneware bodies. 

No. 258 (p. 52). Amador County. lone. Core drill hole No. 61, 
Arroyo Seco Grant. This is a sandy clay containing a large propor- 
tion of ferro-magnesian mineral grains. The residue on 200-mesh is 
18.8%. The plasticity is fair, but sticky, the dry strength is medium, 
and in the dried condition it is medium-hard, medium-grained, and 
open-textured. The colors are: dry, grayish white; wet, l'""f ; cones 
1 and 5, 17"f; cone 9, 17"d ; cone 13, 17"b. At cone 9 and above, 
numerous slag pits appear. Steel hardness is developed between cones 
1 and 5, and less than IQ'/i absorption slightly above cone 5. The fired 
structure is sound, moderately strong, and granular. The total linear 
shrinkage, plastic basis, is 14.2%, at cone 13. The softening point is 
cone 28-29. 

No. 263 (p. 159). Placer County. East of Lincoln. Valley View 
Mine. This is a plastic kaolin that burns nearly white. It contains 
1.2% of + 200-mesh material. The plasticity is good, but Avith a 
tendency to stickiness, the dry strength is medium high, and in the 
dried condition it is medium-hard, fine-grained, and close-textured. 
The colors are- dry, pinkish white; vret, 17"f ; cones 08 and 04, 15"f ; 
cone 1, whiter than 17"f ; cones 7 and 13, slightly whiter than 17'"f. 
It can nearly be classed as a white-burning clay. Steel hardness is 
developed at cone 7 and less than 10';^ absorption at cone 9 (approx). 
The fired structure is sound, stony, and smooth-textured. The total 
linear shrinkage, plastic basis, is 21.4%, at cone 13. The softening 
point is cone 32-33. This clay is suitable for use in terra cotta. Avail 
tile, and possibly in fire brick. 

No. 266 (]). 140). American Refractories Co. "Amreco Fire Clay." 
This is a sample of fireclay from which the "Amreco" brand fire brick 
is manufactured. It contains 32.8% of + 200-mesh sand. The plas- 
ticity is excellent, the dry strength is medium, and in the dried condi- 
tion it is medium-hard, medium-grained, and medium-textured. The 
colors are: dry, 17'"d; wet, 13"'b; cones 010 to 06, 9"f; cone 04, 
15"f, first fading with increasing temperature, then becoming more 
yellowish; cones 11 and 13, ]7'"f. Slight mottling is produced at 
high temperatures by the presence of iron minerals. Steel hardness 
is developed at cone !). The fired structure is sound and moderately 
strong. The .surface texture is slightly rough. The total linear 
shrinkage, plastic basis, at cone 15, is 11.8%. The softening point is 
cone 32. 

No. 272 (p. 163). Riverside County. Alberhill. A. C. & C. Co. 
"Main Tunnel Hill Blue." See also No. 9 in this class and No. 271 
and 274 in class 7. This sample contains more sand and fluxing 



CLAY RESOURCES AND CERAMIC INDUSTRY 



2<)3 



impurities than the other three sami>les of "Hill Blue" clay. The 
percenta^'e of -f-200-mesh sand is 87.0. The plasticity is good, the dry 
strength is medium, and in the dried condition it is medium-hard, 
coarse-grained, and open-textured. There is slight effervescence in 
livdroelilorie acid. The eoh)rs are: dry, 18""f ; wet, 15"'"f ; cones 010 
to 1, 13''f ; cones 3 to 9, 17"f ; cones 11 and 13, 17"d. Steel hardness 
and less than 10% absorption are developed at cone 11. A mottled and 
heterogeneous fired .structure is produced by tlie ]U'esence of a large 
percentage of ferro-magnesian minerals. The fired structure is sound, 
and the surface texture is rough. The total linear shrinkage, plastic 
basis, at cone 13, is 9.8%. The softening point is cone 29. 



Clay 

No. 

9 

14 

27 

33 

34 

53 

76 

78 

81 

84 

92 

97 
102 
108 
130 
139 
145 
150 
197 
257 
258 
263 
266 
272 



TABLE No. 18. 
II. Buff-Burning Clays. 

A. Refractory clays, softening point cone 27 -f. 

a. Open-burning, more than 6% apparent porosity at cone 15. 

6. Medium to higli strength. 



% S.W, 
12.6 
11.6 
15.5 
10.6 

9.0 
25.2 
13.5 
17.4 
16.7 
11.4 
15.0 
11.8 

9.9 
27.1 
14.2 
16.5 
17.4 
20.7 
33.7 
2i.8 

9.7 
21.5 

8.9 
10.2 



% P.W. 
13.3 
12.4 
14.8 
11.4 
13.6 
19.1 
18.1 
19.4 
16.8 
12.7 
13.5 
14.1 
14.0 
13.1 
22.9 
17.8 
21.0 
18.5 
31.9 
19.5 
16.1 
20.0 
15.2 
12.5 











Soften- 










ing pt. 


'c W.P. 


D.T.S. 


% D.V.S. 


% D.L.S. 


in cones 


25.9 


770 


24.8 


7.7 


29 


24.1 


420 


22.6 


6.9 


31 


30.3 


458 


28.6 


8.6 


30-31 


22.0 


550 


20.7 


6.4 


30 


22.6 


449 


17.5 


5.5 


31 


44.3 


795 


42.4 


12.3 


30 


31.6 


240 


23.9 


7.4 


29 


36.8 


462 


29.1 


8.8 


29 


33.5 


414 


30.0 


9.1 


28 


24.1 


326 


22..-. 


7.0 


28 


28.5 


480 


28.8 


S.7 


28 


25.9 


412 


22.3 


7.0 


31 


23.9 


271 


19.0 


6.0 


29 


40.2 


-t-1118 


52.3 


15.0 


27-28 


37.1 


3S7 


22.5 


7.1 


27 


34.3 


201 


28.7 


8.7 


29-30 


38.4 


447 


29.1 


7.8 


30-31 


39.2 


337 


35.7 


10.7 


32 


65.6 


529 


44.9 


13.2 


28 


41.3 


403 


36.7 


11.0 


32 


25.8 


217 


18.1 


.-).7 


28-29 


41.5 


417 


36.2 


10.8 


32-33 


24.1 


231 


16.4 


5.2 


32 


22.7 


348 


19.8 


6.2 


29 



% S.W. = Per cent shrinkage water. 

% P.W. = Per cent pore water. 

%W.P. = Per cent water of plasticity. 

i).T.S. = Dry transverse strength, pounds per square inch, without sand. 

% D.V.S. = Drying shrinkage, per cent dry volume. 

% D.L.S. = Calculated linear drying shrinkage, per cent dry length. 



594 



DIVISION OF MINES AND MINING 



+ « 



M ~ ^ Sf 

M o S £ 



22 O - 5 





Ol 


b£ 


C- 


r! 


o 


c 


.— 


n 


hfi 


Z 
UJ 

-J 
en 








c 

3 
00 


a5 




O 

e 


< 
1- 


3 

03 




^ 










(IJ 


1-) 




— 


>, 


o 


s 


















to 
















a 


c 






































a: 


3 








< 


c: 





u 



o 
O 



O 



o 



o 



o 






6§: 



-0-^ 









^"S 



^'S 






2 OS 

V 



.^- 



6? 












,.» 



03' 6 



Class No., 



c^)!:r:ooico — t^r^r^oo-^r^^-'- 



iO'^iCOiftooc^t— 400cooOTfi— . 



oo»oc^^'^lco — »o^-'-'»crocMQCTf 



»-<-HoorO'-''«t*»co»o^aiOiooo 



00 --o ^ 
oo -^ ci 



I* Ci -^ 

^M h^ ,-4 



■^o-^cjcccc»or-co^--^u^ocooioict— 



00OC0C0»0<MC00St^O.-'iOOOC*J'<J«U300 



u^fM^— '000:7:0:OC'lca;C< 



: CXI C: C-J "* oo 



coooOTt<-*<oaior^.— ■"^QO'-'t^-ocooi^ 



Ciifi'-^OOOOOOlMtMOir-'^OOCO'^'^CCiC^ 



e0C0»COCTsO»0t^Ob->— CO^iOCOOOiO 



"^ C*3 OO W C-l 



OSO i-^cD 






CO ^ 



■^lOOOC^C^U^-^CCOt^OOOCC-^CiThMCOM 



t^COiOC— iSi— 'CO»CO> 



•CO(M-.CiCC<lh-»C'^''-< 



CO t^ 

ooeo 



t^CC»0"«*CDC0'^CC00 00O0:c0Q0OTj*!Dc0t>--^*'OeDC0(M 



00 r- ?o »c c^ (X) c 



CQ-rt-^jTCOO^OOiC^-OOC^rfCO — r-tMOOlOlO 



r^C0t-OcDC<»0'JC^tDTr»0C^»-'0iC0'irTt<»0»-> 

+ - ~ + 



OiCOi— ";CC:C^:D-^-^C<jTt>0— 'OOiC'^O 



OTj*l>.cOt^t^-.OC^J:CiOO'— 'OO'-'OOCOOOCO 

+ + I 



00 O O — « O O lO : 



;c-)C>T»ooc»CfMcor^co»c 



dOt-Xi-^OOI^OO'-HCOcO^'-'OS-^QOO-^-^ 

c^c^coO(MTi«c^coTfO^"0-*io — o«; — 

+ + I 



OOt^^O^S— •■^«C'^C^OO^C»C-^' 



ioi>-a5cot^t--coiot^eoiO'*oi'^cooiO'— ' 

+ I +1 



t~-O'^'-*C^:DCCiC0i'}«C^r-0:C0»C*C00'^ 



tcooroo r:»or^coooa;'-«'Oi^'*':sr-io 

[ III 



■«* 00 

eoeq 



+ 






OO i^O 



■ T-« to 

i o o 



03'*r-corfco:ooO'-'T^(Mr*«ooooiW30i-»t>-ooco«oc^ 
— c^jeoco»ot^t^oooooiOsoOfocc-rr'tcciioi.o:coi-^ 



+ 



o 

o 

* 



+ 



o 



0,, 

II 






CO 

> 



CLAY RESOURCES AND CERAMIC INDUSTRY 



295 



Absorption and linear shrinltage curves for clays of class 6. 



010 08 Oh Of OZ. I 3 5 7 9 II 15 /£■ 



I 

a: 

i 



I 

I 



20 

JO 


10 
10 


20 
10 


20 
10 





5 

** oU^ 





1 — 








1 

No 


9 


1 — 














A 


">v 
















J 












S 




^- • 


■ " — 


>•- 


-.. 


' — 




l—i 


< 






A 






No 


14 


















^ 














T. 


















L!, 








• -• 


— 


.— 






A 






No 


27 


















"^ 


^ 




















.5. 




,» • 


... 


... 


... 


■^^ 


rr- 


<. 


>< 












No 


35 
















A 




^ 




" 




























— ■ 








S^ 




^m* 


.-4 


.. 


-- 


. * H 


-- 


^ 


__ 



010 08 0b Of OZ I 3 5 7 9 II 13 /T 



^, /O 

5 o 

5: 
t" 

I 

c: 20 

I 







A 


1 


Noj34 








r- 








"^ 


■^ 








-= 


... 


> 










J. 




.-' 


... 


... 


• • • 


... 




.^ , 


^ 


S» 




No|s5 

I 








■■■' 










V 


"V 




















,S. 


^» 


,-• 


j 


■"" 


... 


... 


"^r 






A 






NoJ76 








— ■ 










N 


\ 




















S 


_.. 




... 


.-- 


;.v 






- 


— 


A, 


\, 




No 


76 


















\ 






— 


^ 














.?. 


^*' 


-- 


... 




"' 


^ 


t^,/- 



//£AT TREfiH'nENT IN CONES. 



H[/\T TREfiTnENT IN CONES. 



CM 08 Ob Of Ol I 3 S 7 9 II n IS" 



010 08 0b Of ai I 3 5 7 9 II 13 S 



0^ 20 
«5> /o 
§ 

%20 
^ 20 

« /o 
^' o 

I 

C; 20 

I 
^ /o 

% 







A 






No 


fii 




















\ 


a.^ 


















s 




.'' 




... 


"^ 


rrr 


rrr 


'^^^ 
































A 






No 


84 


















> 








S 








M 

- - 


rr 


rr 


f«-<; 








A 


























, [Noj8£ 






> 












h-i^ 




... 


S 




1 


... 


T"" 






A 






1 

Horn 






1 






"" 


^"'** 






■— 




-- 




«.^ 


s 










^ 


BAa 




... 


- 


•-- 


... 




... 






//EAT TREfiinENT IN CONES. 



HEAT TREATMENT IN CONES. 



296 



DIVISION OP MINES AND MINING 



Absorption and linear shrinkage curves for clays of class G. 



ft; 

I 

i 



0100806 Of OZ / J S 7 9 // 13 /r 



I 
I 



30 
20 
10 

3^ 

zo 

10 



3d 

20 

10 















No 


14 


5 










-. 




A 


N. 


1 
1 






























\^ 


_> 
















... 


-S 


--- 





--" 


""* 








<. 


— 












No 15 

















A 






1 


















\ 


^ 




















.S- 


,'• 




■~ 


r» 


< 


-- 


- 




y> 
















No 


19 


7 






A 






\ 


















































_ 




S 


*M. 



















HEfiCT TREPJnENT IN CONES. 



s 

5 10 
^ zo 

lo 

^ 20 

•« 

t" 10 

lo 

I 

5s 10 
% 
^ 



0)0 08 Ob 0^ OZ / 3 S 7 9 II 13 /£- 













A_ 




^ 


d^t 










— - 


.5. 


— 




--- 


s-t 
















A 


TTZ 




No 


25 S 












— - 


's 


■■ 


i>— « 
























No 


26 


3 


















^*^ 
5 




^^ 




^^ 




— 


... 


-- 




-— 








*^ 


















A 






No 


26 


6 














-— 




- 


















• — 


.?.-- 


... 


-- 


... 


.-• 


__ 








— ■ 


■— M 


A 


^ 


No 


272 
























^ 


_S 


. * 


■ - 




~ 





/VEAT TREAmENT INCOMES. 



b. Dense-Burning, Less Than 6% Apparent Porosity Between 

Cones 10 and 15. 

7. Mainly Medium to High Strength. 

No. 13 (p. 163). Riverside Conntv. Alberhill C. & C. Co. "Extra 
Select :Main Tunnel." See also No. 15 and 29 in class 2. This clay 
is hand sorted from the main tunnel fireclay bed, in order to prepare 
a grade for the market that has better fired colors than the run-of-mine 
material, but for some undetermined reason the sample is distinctly 
inferior as to color, compared to No. 15 and 29. It is used principally 
in the manufacture of art tile, and to some extent in firebrick. It has 
excellent plasticity, medium dry strength, and a sandy, open texture 
in the drv condition. It contains 2.6' r of -|-200-mesh sand. The colors 
are: dry, 17'"^f; wet, 17'"'b; cones 010 to 06, ll'f; cone 01, 17"f; 
cones 02 to 18, 17"'19'"f. Finger-nail hardness is developed below 
cone 010, and steel hardness is approached at cone 7, but vitrification 
is not complete until cone 15 is reached. The total linear shrinkage, 
plastic basis is 14.5% at cone 15. The softening point is cone 29-30. 
The best firing range is from cone 7 to cone 15. 

.Vo. 55 (p. 203). San Diego County. Near Carlsbad. Pacific Clay 
Products Co. "Kelley Ranch White." Tliis is a butf-burning clay with 
excellent plasticity, suitable for the manufacture of face brick and 
fire brick. It contains 2.6/r of +200-mesh sand, has medium dry 
strength, and in the dry state it is soft, fine-grained, and dense. The 
colors are: dry, 11"; wet, 5"; cones 010 to 01. 7"f; cone 02, 5"f; 
cone 1, 9"f ; cone 3, 13"f ; cones 5 and 7, 17"f ; cones 9 and 11, 17"d; 
cone 13, 15"d. A pleasing assortment of buffs, creams, and yellow- 
browns is obtained by varying the firing conditions. Finger-nail hard- 
ness is obtained below cone 010, and steel hardness develops at cone 1. 
The fired structure is sound, fine-grained, and above cone 1, it is stom-. 



CLAY RESOURCES AND CERAMIC INDUSTRY 297 

The total linear shriiikajie, ])]astie basis, at cone 15 is 17.99r. The 
softeninff point is cone 29. The best firinfj range is from cone 1 to 
cone 1"). 

Xo. 56. German fireclay, used by Atlas Fire Brick Co. This is 
a fine-<rrained clay with a smooth and stronji' i)lasticity, medium- 
hi{rii dry strength, and a hard, fine-grained, close-textured dry con- 
dition, with a slight tendency to laminate. It contains 2.8'/^ of -|-200- 
mosh sand. The colors are: dry, whiter than 17""f wet, 17""f ; cones 
010 to 1, somewhat whiter than 17"'f ; cones 3 and 5, 19"f ; cones 7 to 
18, 17" 'f. The fired structure is stony, and with the firing schedule 
used, one or more large cracks developed in many of the test pieces. 
Finger-nail hardness develops below cone 010, and steel hardness at 
cone 06. Absori)tions below 10.0% appear at cone 1. The total linear 
shrinkage, plastic basis, at cone 13, is 11.9%. The softening point is 
cone 27. The best firing range is from cone 06 to cone 13 and above. 
The clay is particularly well suited for use as a firebrick bond. 

Xo. 80 (p. 174). Riverside County. Alberhiil. L. A. B. Co. "Plastic 
Pink and Yellow." This is a buff and gray-burning refractory clay, 
containing but 2.6'^ of -|-200-mesh sand, and with smooth and strong 
plasticity. The dry strength could not be accurately determined with- 
out adding sand, as incipient lines of weakness are developed during 
air-drying. With 50 /( of — 20-mesli to -|-30-mesh Ottawa sand, the 
bonding strength is 56 lb. per s(|. in. In the dried condition, it is medium 
soft, fine-grained, and close textured. The colors are: drv, 13"d ; wet, 
13"; cones 010 to 04, 7'd ; cones 02 to 5, 7"d ; cone 7, 9"'f; cones 9 to 
13, 17""f. Steel hardness is developed below cone 010, absori)tions of 
less than lO'/f are i)resent at cone 3 or above, and vitrification is com- 
plete at cone 9. All fired test pieces are severely shattered, and broken 
into several pieces. The fired structure is stony and brittle. The 
maximum total linear shrinkage, plastic basis, was noted at cone 9, 
25.0% , but on account of the serious shattering of the test pieces at 
cones 11 and 13, which invalidated the accuracy of measurement, it is 
likely tliat the true value of the shrinkage at these latter temperatures 
is higher than at cone 9. The softening point is cone 33. The clay is 
similar in many respects to No. 273 in class 3 (Alberhiil SII-4), except 
that it contains more iron. It is a useful bond clay in buff-burned ware, 
but can not be used alone. 

Xo. 83 (p. 114). Riverside County. Alberhiil. L. A. B. Co. "Main 
Pit Red." This is a pla.stic, light-re(l-l)uriiing clay of value in the 
manufacture of roofing tile, face brick, hollow building tile, and similar 
products. It contains 11.69^ of -|-200-mesli sand, and has a smooth 
and strong plasticity. The dry strength is medium, and the dried 
condition is medium hard, dense, and fine-grained. The colors are: 
dry, 5"b; wet, 5"; cones 010 to 02, 5'd; cones 1 to 5, 7'd; cones 7 to 
13, ll"d. Finger-nail hardness appears below cone 010, and steel 
hardness at cone 1. Absor])tious below 10% a))pear at cone 5. The 
fired structure is dense and stony, and is sound up to cone 3. At 
higher temperatures, the test pieces are broken into two or three 
pieces. The total linear shrinkage, plastic basis, at cone 13, is 18.3%. 
The softening point is cone 29. The best firing range is from cone 1 
to cone 5, but slow firing to cone 13 Avill doubtless result in sound 
structures and thorough vitrification. 



298 DIVISIOX OF MINES AND MINING 

A"o. 85 (p. 174). Riverside County. Alberhill. L. A. B. Co. "Pink 
Mottled." Til is is a plastic, bulT-burning clay that has wide uses in 
sewer-pipe, hollow-tile, pottery, flower pot, and face brick mixes. The 
plasticity is excellent, the dry strength is medium, and the dry con- 
dition is soft and fine-grained. It contains 3.4% of 4-200-mesh sand. 
A tendency to laminate was noted. The colors are : drj% 7"d ; wet, 
9"b; cones'OlO to 04, 9'b; cone 02. 7'd ; cones 1 to 5, 7'f ; cone 7, ll'f ; 
cones 9 to 18, 13'f. Finger-nail hardness is developed below cone 010, 
and steel hardness at cone 1. Less than 10% absorption is present at 
cone 7. The total linear shrinkage, plastic basis, at cone 13, is 18.3%. 
The softening point is cone 31-32. The best firing range is above cone 1. 

No. 101 (p. 171). Riverside County. Alberhill. G., :\IcB. & Co. 
"Sloan White." This is a bulf -burning face brick or fire brick clay with 
excellent plasticity, medium dry strength, and a medium hard, fine- 
grained, close-textnred, drv condition. It contains 7.0% of -{-200- 
mesh sand. The colors are: drv, 17'"f ; wet, 17""d; cones 010 to 02, 
9''d ; cone 1, 13''f ; cones 3 to 11, 17''f ; cone 13, 17"d. Finger-nail hard- 
ness appears below cone 010, and steel hardness develops at cone 3. The 
fired condition is sound, stony, and smooth-textured. The total linear 
shrinkage, plastic basis, at cone 15 is 17.5%. The softening point is 
cone 30. 

No. 110 (p. 176). Riverside County. Alberhill. P. C. P. Co. "Doug- 
las." This is a plastic fireclay, similar to No. 104 (class 5) but not 
quite so refractory. It is also related to No. 27 (class 6) and No. 273 
(class 3), but differs from these in several important respects, as will be 
noted by a close study of the data. It contains 3.4% of -f 200-mesh 
sand. The plasticity is very good, the dry strength is medium, and the 
dried condition is medium-hard, fine-grained, and close-textured. The 
colors are : dry, 13""b ; wet, 13"" ; cones 010 to 02, 7"d ; cones 1 and 3, 
7"f ; cone 5, i7"f ; cones 7 to 11, 21"'f ; cone 13 slightly darker than 
cone 11. Steel hardness develops at cone 06. Absorptions below 10% 
develop at cone 3 and above. All fired test pieces are badly shattered, 
and broken into two or more pieces. The texture is smooth, and 
peppery with finely divided specks of iron. The total linear shrinkage, 
plastic basis, at cone 13, is 22.5%. Slight bloating was noted at cone 
15. The softening point is cone 32-33. The clay is used for stone- 
Avare and pressed brick. 

No. 133 (p. 63). Amador County. lone (Carbondale). Yos. P. C. 
Co. "Harvey Clay." This is a buff -burning fireclay with good 
plasticity, medium-low dry strength, and a medium-hard, fine-grained, 
close-textured dried condition. It contains 6.8% of -|-200-mesh sand. 
The colors are: drv, 9""f : wet. 5""d ; cones 010 to 06, 13"f ; cones 04 
to 1, 17'"f ; cones 3 to 7, 19"f ; cone 9, 21'"f ; cones 11 and 13, 17""f. 
Steel liardne.ss develops at cone 1, and less than 10% absorption at 
cone 3. The fired structure is stony and sound, except at cones 11 and 
13, at which small tension cracks ajjjH'ar. Blistering is noticeable at 
cone 13. The maximum total linear shrinkage, plastic basis, is 24.5% 
at cone 11. The softening point is cone 33. The best firing range is 
from* cone 1 to cone 11. The clay may be used in fire brick, terra cotta, 
face brick, etc. 

No. 149 (p. 156). Placer County. Lincoln. Lincoln Clay Products 



CLAY RESOURCES AND CERAMIC INDUSTRY 299 

Co. "No. 9." This clay is .similar to No. 14G in class 8, but does not 
vitrify so completely at cones 9 to 13, nor can blistering be detected at 
cone 13, but bloatinjr is apparent at cone 15. The total linear shrinkage, 
plastic basis, at cone 13, is 19.9 '^t. The softening point is cone 31-32. 

No. 153 (p. 147). Placer County. Lincoln. Clay Corporation of Cali- 
fornia. See No. 152 and 280 in class 8. This sample has lower refrac- 
toriness, slightly more sand, and more coloring matter than No. 152. It 
contains 25.0% of +200-mesh sand. The plasticity is excellent, tlie dry 
strength is medium-high, and in tlic dried condition it is medium-hard, 
medium-graiiu'd, and open-te.xtured. The colors are: dry, 21'"f ; wet, 
19"d ; cones 010 to 1, ll'd ; cones 3 and 5, 15'M ; cones 7 to 13, 17''d. 
Steel hardness is deveh)ped at cone 1. Less than 10% absorption 
appears at cone 7. The fired structure is sound, stony, and the fired 
.surface texture i.s sligldly rougli. The maximum total linear shrinkage, 
plastic basis, is 21.0% at cone 11. The softening point is cone 30. The 
best firing range is from cone 1 to cone 11. 

No. 156 (p. 151). Placer County. Lincoln. Gladding, ^McBean & Co. 
"Fire-proofing Clay." Tins is a plastic, low-grade buff-burning fireclay 
that is used in various bodies to increase the refractoriness of the mix- 
ture. It contains 8.4% of -f200-mesh sand. The plasticity is good, the 
di-y strength is medium-high, and in the dried condition, it possesses 
finger-nail hardness, is fine-grained, and close-textured. The colors are: 
dry, 17"d ; wet, 17"b ; cones 010 to 5> ll'd ; cones 7 and 9, 17'"d ; cones 
11 and 13, 17'''b. Steel hardness is developed at cone 02. Less than 
10% absorption appears at cone 1. The fired structure is sound and 
stony. Slight blistering appears when fired under neutral or reducing 
conditions to cone 11 and 13. The fired surface texture is slightly 
rough. The maximum total linear shrinkage, plastic basis, is 18.9%, 
at cone 9. The softening point is cone 28-29. The best firing range is 
from cone 02 to cone 9. 

No. 204 (p. 151). Calavera.s County. Valley Springs. California 
Pottery Co. "Blue Plastic." The properties of this clay are closely 
similar to those of No. 203, in class 14, but it contains less iron, which 
results in lighter fired tones, and in greater refractoriness. It contains 
1.0%, of +200-mesh material. The colors are: dry, 17"d ; wet, 17"b; 
cones 010 to 04, 9"d ; cones 02 to 7, 13"d ; cone 9, 15"d. The total 
linear shrinkage, plastic basis, is 18.4%, at cones 11 and 13. The soft- 
ening point is cone 27. This is an excellent clay for buff-burned face 
brick and roofing tile. 

No. 213 (p. 59). Amador County. lone. Eckland pit. This is a 
buflF-burning clay with smooth and strong ])lasticity, and medium-low 
dry strength. In the dried condition it is medium-hard, fine-grained, 
and close-textured. The residue on 200-mesh is 12.6%. The colors are : 
dry, 13"d ; wet, 15'' ; cones 010 to 02, ll'd ; cones 1 to 7, 13"f ; cones 
9 to 13, 17"d ; strongly nu)ttled with iron specks. Steel hardness is 
developed at cone 3, and less than 10% absorption at cone 13. The 
fired structure is sound and stony, except at cones 11 and 13, when a few 
large cracks appear in the fired test pieces. The surface texture is 
smooth until cone 9 is reached, when the reduction of the non-plastic 
ferro-magnesian minerals causes a pitted surface. The total linear 
shrinkage, plastic basis, at cone 13, is 22.1%. The softening point if 



;^00 DIVISION Ol'' MINES AND MINING 

cone 31. The best firing- range is from cone 3 to cone 8. The clay is 
suitable for face brick and faience tile mixes, and could be used in 
some fire brick mixes. 

No. 229 (p. 174). Riverside County. Alberhill. L. A. B. Co. "No. 7 
Pit." This is a buff-burning i)lastic fireclay that is suitable for face 
brick or fire brick manufacture. There is slight effervescence in hydro- 
chloric acid. It contains 0.8'/^ of -|-20()-mesh sand. The plasticity is 
smooth and strong, the dry strength is medium-low, and in the dried 
condition it is medium-hard, fine-grained and close-textured. The 
colors are : dry, 9"d ; wet, 7"b ; cones 010 to 06, 5'f ; cones 04 to 3, 5''f ; 
cones 5 to 9, 17"f ; cones 11 and 13, 17"(1. Steel hardness is developed 
at cone 1, and less than 10'^{ absorption at cone 9. The fired structure 
is sound and stony, and the surface texture is smooth. The total linear 
shrinkage, plastic basis, at cone 13, is 20. 4'/^ . Slight bloating appears 
at cone 15. The softening point is cone 32. 

No. 230 (p. 174). Riverside County. Alberhill. G., McB. & Co. 
East Pit. "No. 9 Clay." This is a buff -burning refractory clay with 
smooth and strong plasticity, and medium-high dry strength. It con- 
tains 2.0 9( of -|-200-mesh sand. In tlie dried condition it is medium- 
hard, fine-grained, and close-textured. The colors are : dry, 13""d ; 
wet, 17""d; cones 010 to 04, pinkish white; cones 02 to 7, yellowish 
white; cones 9 and 11, 19"f ; cone 13, 17'"d. Steel hardness is devel- 
oped at cone 02, and less than 10% absorption appears below cone 5. 
The fired structure is stony, and all test pieces are broken into two or 
more pieces by fracturing. The total linear shrinkage, plastic basis, at 
cone 13, 17.5 % • The softening ])oiut is cone 32-33. The clay can not 
be used alone, but when mixed with non-plastic material, it is an excel- 
lent clay for face brick, fire brick, and terra cotta. 

No. 245 (p. 52). Amador County. lone. Core drill hole No. 55-1. 
Arroyo Seco Grant. This is a buff-burning clay with good, but sticky, 
plasticity and medium dry strength. In the dried condition it is soft, 
friable, fine-grained, and close-textured. The colors are: drv, buff- 
Avhite; wet, 17""f; cone 1, 19"f; cones 5 and 9, 17"d; cone 13, 15"i. 
Steel hardness develops below cone 1, and less than 10% absorption 
between cone 1 and cone 5. The fired structure is sound and stony, and 
the surface texture is smooth. The total linear shrinkage, plastic basis, 
at cone 13, is 19.0% . The softening point is cone 30-31. It could be 
used in face brick, terra cotta, tile, and fire brick. - 

iVo. 545 (p. 52). Amador County. lone. Core drill hole No. 55-3, 
Arroyo Seco Grant. The plasticity is good, but sticky ; the dry 
strength is medium, and in the dried condition it is soft, friable, fine- 
grained, and close-textured. The colors are : drv, gravish white ; wet, 
15"'"f; cones 1 and 5, 19"f; cone 9, 17""f; cone 13, 17""d. Steel 
hardness is developed below cone 1, and less than 10%) absorption is 
jiroduced between cone 1 and cone 5. The fired structure is sound and 
stony, and the surface texture is smooth. The total linear shrinkage, 
plastic basis, at cone 13, is 16.7% . The softening point is cone 29. 

No. 247 (p. 52). Amador County. lone. Core drill hole No. 55-2, 
Arroyo Seco Grant. This is similar to No. 246, but has greater 
shrinkage, a higher softening point, and effervesces slightly in hydro- 



CLAY RESOURCES AND CERAMIC INDUSTRY 301 

chloric acid. Tin* total liiicai- shrinkage, plastic basis, at cone 13, is 
19.5Vc. The softenino: point is cone 32. 

No. 2iS (]). 52). Amador Connty. lone, ("ore drill hole No. 56-1, 
Arroyo Seeo Grant. Tlic plasticity is good, the dry strength is 
medium high, and in the dried condition it is medium-hard, fine- 
grained, and clo.se-textured. A ]>art of the sample consists of soft grains 
of partly kaolijiized matter tluit is not rendered i)lastic by the usual 
methods of preparation. This results in a heterogeneous structure. 
The colors are: dry, 17'"f; ^vet, 17"'d ; cones 1 and 5, 17"d; cones 9 
and 13, 17""h. Steel hardness is developed below cone 1, and less than 
lO'/r absorption appears between cone 1 and cone 5. Blistering is 
noticeable at cone 13. The maximum total linear slirinkage, plastic 
basis, is 21.1 /r, at cone 9. The softening point is cone 30-31. It is 
suitable for the manufacture of terra cotta and tile, but is not suitable 
for making a good fire brick. 

No. 249 {\).b2). Amador County, lone. Core drill hole Xo. 56-2, 
Arroyo Seco Grant. This is very similar to No. 245, and does not 
require a separate description. The total linear shrinkage, plastic 
basis, is 18.2'/ at cone 13. The softening point is cone 30-31. 

iVo. 55c? (p. 52). Amador County, lone. Core drill hole No. 57-3, 
Arroyo Seco Grant. This is similar to No. 136 (class 8) and 240 
(class 4), with the differences as noted. There is slight effervescence 
in hydrochloric acid. The colors are: dry, pinkish white; wet, yellow- 
ish white; cone 1, nearly white; cones 5 and 9, 19"f; cone 13, 17"'b. 
Steel hardness and less than 10/r absorption are developed between 
cones 1 and 5. Xo firing cracks were noted. The total linear shrinkage, 
plastic basis, is 21.5%, at cone 13. The softening point is cone 31-32. 

No. 254 (p. 52). Amador County, loiu'. Core drill hole X"o. 57-4. 
Arroyo Seco Grant. Tliis sample contains more coloring matter and 
more non-plastic ferro-nuignesian minerals than No. 253. There is 
slight effervescence in hydrochloric acid. The i)lasticity is good, the 
dry .strength is medium, and in the dried condition it is soft, fine- 
grained, and open-textured. The colors are: drv, 17"f; wet, 17"'f; 
cone 1, 15"f ; cone 5, 17"'d ; cone 9, 17""d ; cone 13, 17"'b. Steel hard- 
ness appears below cone 1, and less than 10% ab.sorption is developed 
between cone 1 and cone 5. The fired structure is sound and stony, 
except that at cone 13, one large crack developed in the test piece. 
Blistering is noted at cone 13. The maximum total linear shrinkage, 
pla.stic basis, is 21.6' v, at cone 9. The softening point is cone 31. This 
is a suitable clay for face brick, terra cotta and tile. 

No. 271 (p. 163). Riverside Countv. Alberhill. Alberhill Coal & 
Clay Co. "Lower Tunnel, Hill Blue." See also No. 9 and 272 in class 
6, and No. 274 in this class. The plasticity of No. 271 is smooth and 
strong, the dry strength is medium-high, and in the dried condition it 
is hard, fine-grained, and close-textured. It contains 2.0% of -|-200- 
mesh sand. There is slight effervescence in hydrochloric acid. The 
colors are : dry, 13"" f ; wet, 5""f ; cones 010 to 9, 17"f ; cones 11 and 13, 
21""d. Steel hardness is developed at cone 1, and less than 10% 
absorption at cone 5. One or two of the test pieces show small cracks, 
otherwise the fired structure is sound and stony, and the surface texture 



302 DIVISION OF MINES AND MINING 

is siuootli. Tlie total linear slirinka<?e, plastic basis, is 11. H%, at eonc 
13. The softening point is cone 31-32. For uses, see No. n, in class 6. 

No. 27i (p. K;:}). Hiv(M-si(l(> ("(.imtv. Albcrliill. A. ('. & ('. Co. 
"Upper Tunnel Hill Blue." See also No. 9 and 272 in class 6, and No. 
271 above. No. 274 is intermediate between No. 271 and 272 in its 
content of sand and its ceramic properties. The dry strength is 
medium. There is no effervescence in hydrochloric acid. Tlie sample 
contains 11.4% of -f-200-mesh sand. The colors are: dry, I'^'^f ; wet, 
ir)'""b; cones 010 to 06, 15"f ; cones 04 to 9, 17"f ; cones 11 and 13, 
17"d. Steel hardness is developed at cone ;1, and le.ss than 10% absorp- 
tion at cone 9. The fired structure is sound, sliglitly heterogeneous, and 
the surface is slightly rough. The total linear shrinkage, plastic basis, 
at cone 13, is 19.8%. The softening point is cone 30. Tliis is a suitable 
clay for fire brick, face briclv and terra cotta. 

c. Dense-Burning, Less Than 6 Per Cent Apparent Porositv 

Between Cones 5 and 10. 

8. Medium to High Strength. 

No. 121 (p. 53). Amador County, lone. Arroyo Seco Grant. Jones 
Butte. Leased by Stockton Fire Brick Co. "Unctuous Clay." The 
available quantity of this clay is insufficient for commercial production, 
but a sample was tested as a matter of general interest. It has a smooth 
and strong plasticity, medium dry strengtli, and in the dried condition 
it is medium-hard, fine-grained and close-textured. The colors are : dry, 
nearly white ; wet, 21'"f ; cones 010 to 06, pinkish white ; cones 04 to 9, 
yellowish white ; cones 11 and 13, I'^'^f . Steel hardness is developed at 
cone 04. Less than 10.0% absorption appears at cone 5. The fired 
test pieces are stony below cone 11, and glassy at cone 11 or above. 
They are sound, but seriously warped. The total linear shrinkage, 
pla.stic basis, at cone 13, is 25.6%. The softening point is cone 33. 
The clay is closely similar to some of the varieties that are mined at 
Lincoln, Placer County, especially No. 146, post. 

No. 124 (p. 56). Amador County. lone (Carbondale). Leased by 
G. A. Starkweather. "Yarn No. 1." This is a piuk-and-cream burning 
clay with smooth, moderately-strong plasticity and medium dry strength. 
It contains 1.0% of +200-mesh sand. The dried condition is soft, 
"soapy," fine-grained and open-textured. A strong tendency to warp 
and to laminate was noted. Tlie colors are: drv, 2V"i; wet, 21''"d; 
cones 010 to 04, 9'f ; cone 02, 17"f ; cones 1 to 1, 17"d ; cones 9 to 13, 
19"f. Steel hardness is developed at cone 1. Less than 10% absorption 
appears at cone 3. The fired structure is generally sound, but a few 
pieces split in firing. The total linear shrinkage, plastic basis, at cone 
13, is 20.8 7('- The softening point is cone 32. The best firing range is 
above cone 1. The claj'' is suitable for fire brick, terra cotta, stone- 
ware, etc. 

A'o. i55 (p. 58). Amador County. lone (Clarksona). N. Clark and 
Sons. "Dosch." This clay has been well knoAvn for many years in 
the pottery, stoneware, and terra cotta industries. It contains but 1.2% 
of -j-200-mesli sand. It is smooth and has strong plasticity, medium 
dry strength, and in the dried condition it is medium-hard, fine-grained, 



CLAY RESOURCES ANI> , ifiRAMIC INDUSTRY 303 

aiul close-textured. Tlie colors are: dry, yellowish Avhite; wet, 17"'f; 
eone 010, 17"f, becomin}? nearer to wiiite with increasinrr firing tem- 
l)erature. approximating? 19"f at cone 3; cones 11 -and 13 (flashed) 
17"'. Steel hardness ai>pears at cone 1. and less tlian 10',' absorption 
at cone 3. The fired structure is sound, stony and smooth-textured. 
The maxinmm total linear shrinkage, plastic basis is 21.0% at eone 13. 
Slio-ht bloating was noted at cone 15. The softening point is cone 31. 
The l)est firing range is from eone 1 to eone 13. Tlie clay can be ca.st 
and jiggered. 

No. lie (p. 156). Placer County. Lincoln. Lincoln (May Products 
Co. "Xo. 1-6." This is the best known variety of Lincoln clay at the 
present time. It is shipped to all parts of the Pacific Coast for use iu 
stoneware, pottery, faience tile, terra cotta, fire brick, and other pur- 
poses. It is an excellent clay for casting and jiggering. The plasticity 
is smooth and strong, and it contains but 0.6% of --f-200-mesh sand. The 
dry strength is medium, and in the dried condition it is soft, fine- 
grained and close-textured, with a talcv feel. The colors are : dry, 
buff- white ; wet, 17''d ; cones 010 to 04, ll"f ; cone 02, 13"f ; cones 1 and 
3, 17"f; cone 5, 17'f; cones 7 and 9, 21"'f; cone 11, 17""f; cone 13, 
13""f. Steel hardness is developed at cone 1. Less than 10% absorp- 
tion appears at cone 3, and vitrification is complete at cone 9. Slight 
blistering is noticeable on test pieces fired under reducing or neutral 
conditions at cones 11 to 15. The fired structure is sound and stony. 
The maximum total linear shrinkage, plastic basis, is 21.5%, at cone 11. 
The softening point is cone 31-32. The best firing range is from cone 
1 to cone 11. The long vitrification range, the excellent plasticity, and 
the ability to withstand abuse in drying and firing, are the important 
advantages that this clay possesses to a greater degree than any other 
clay in the state that is available in commercial quantities to the entire 
iiulustry. The same is true of Xo. 280, see po!il. 

No. 147 (]). 156). Placer County. Lincoln. Lincoln Clay Products 
Co. "Xo. 7." This clay is very similar to Xo. 146, but fires to slightly 
darker tones. It is used in faience tile, face brick, and sewer-pipe 
mixes, but is not quite as suitable for casting and jiggering as No. 146. 
The colors are: drv, 9"d ; wet, 13'"b; cones 010 to 04, 5'f ; cones 02 and 
1, ll"f; cone 3, i5"f; cone 5, 17"f; cones 7 and 9, 17'"f; cone 11, 
17""f; cone 13, 13""d. Steel hardness is developed at cone 1, and 
less than 10% absorption is developed at cone 3. Vitrification is com- 
plete at cone 9 — , and blisfei-ing is well develojied at cone 13. The 
maximum total linear shrinkage, plastic basis, is 21.4%, at cone 11. 
The softening point is cone 31. 

No. 1.51 (p. 156). Placei- County. Lincoln. Lincoln Clay Products 
Co. "Wa.shed China Clay. ' ' This sample was supplied by Mr. Dillman 
from a warehouse stock of some material that was prepared some years 
ago by washing the Xo. 1-6 (sample X'^o. 146) clay, in an attempt to 
produce a china clay for the local market. The color was improved 
slightly by this treatment, but not sufficiently to permit the use of 
the clay as a substitute for English china clay, and the shrinkage was 
increased greatly beyond the already high shrinkage of the crude clay. 
Slight blistering appears at cone 11. The maximum total linear shrink- 
age, plastic basis, is 25.6%, at cone 9. The softening point is cone 30. 



^04 DIVISION OF MINES AND MINING 

There is slifi:lit effervescence in liydrochloric acid. Sfuiniiiiii^- was not 
noticed, as in the majority of the crude Lincoln and lone clays, but no 
special tests Avere-inade to determine if washing? iuid completely removed 
the vaiuidium salts which have been stated to be the cause of scumming 
of these clays/ 

No. 152 (p. 147). Placer County. Lincoln. Clay Corporation of Cali- 
fornia. This samjile of plastic fire clay, toji'cther with Xo. 15:} (class 
7), was taken from the i)it a])pi-oach durinf>' the i)relimiiuiry develop- 
ment of this ])roperty. Tlie test results should be comi)ared with those 
of Xo. 280, which sample was sui)plied by the company from the ware- 
house after full-scale production had been i-eached. Xo. 152 has excel- 
lent plasticity, medium-hijih dry streno'th, and in tlie dried condition it 
is soft, fine-<irained, and oi)en-textured. It contains 23.6';, of -|-2()0- 
mesh saiul. The colors are: dry, nearly white, wet, 17"'f; cones 010 
to 02, i)inkish white; cones 1 to 7, 17'f; cones 9 to 13, 17"'f. Steel 
hardness ap])ears at cone 1. Less than lO' ,' absorption is developed at 
cone 1. Slight blistering is a])])arent at cone 13. The fired structure 
is stony, and most of the fired test ])ieces contain one or more large 
cracks, some of which cause rujiture of the test piece into two or more 
fragments. The maximum total linear shrinkage, plastic basis, is 
26.4',y , at cone 11. The softening jjoint is cone 33. It was stated by 
the comjiany that as a rule the softening ])oint of this clay is below cone 
29, so that the sample obtained for testing may not be re]U'esentative. 

No. 157 (p. 151). Placer County. Lincoln. Gladding, :\IcBean & Co. 
"Terra Cotta Clay." This corresponds to Xo. 146, and is used as the 
basis for terra cotta and faience tile body mixes. It contains 2.2% of 
-f-200-mesh sand. The plasticity is (>xcellent, the dry strength is 
medium, and in the dried condition it is medium-hard, fine-grained, and 
close-textured. The colors are: drv, 17"f; wet, 17"d; cones 010 to 1, 
ll"f; cones 3 to 9, 17"d; cones 11 and 13, 17""d (flashed). Steel 
hardness is developed at cone 04. and less than 10*;, absor])tion apjiears 
at cone 3. The fired structure is sound and stony, excei)t that a few 
small cracks ai)peared in some test j)ieces during firing. The fired sur- 
face texture is smooth. Slight blistering is noticeable at cone 13. The 
maximum total lineai- shrinkage, plastic basis, is 23.6%, at cone 13. 
The softening point is cone 32-33. 

No. 175 (p. 65). Butte County. Oroville. Table ^Mountain Clay 
Products Co. This is a plastic, buff-burning clay from the lone fornui- 
tion. The plasticity is smooth and strong, the dry strength is nu'dium, 
and in the dried condition it is soft, "talcy, " fine-grained, and close- 
textured. It contains 2.4^, of -|-200-mesh sand. The colors are: drv, 
]7"f ; wet, 15"d; cones 010 to 04, 7'f ; cone 02, ll'f ; cones 1 to 5, 15'd; 
cones 7 and 9, 15"d ; cones 11 and 13, 17"'b. Steel hardness is devel- 
oped at cone 02, aiu1 less than 10*^,' absorption at coiu' 1. The fired 
structure is stony, and the surface texture is exceptionally smooth. Up 
to cone 7, all test pieces are sound, and at cone 7 and above, each test 
piece is fractured into two or more fragments. The total linear shrink- 
age, i)lastic basis, at cone 13, is IS. 9'^ . Bloating is ]ironounced at cone 
15. The softening point is cone 30-31. The best firing range is from 

'See Currv, E. R., Notes on Green Scummins: .Tour. Am. Cer. Soc, Vol 9, p. .^92, 
192G. 



(LAY RESOURCES AXD CERA^flC INDUSTRY 305 

cone 02 to I'onc l:?. Since tlie sainplc was taken near the surface durinf; 
tlic |)reliniinary developnieiit of the i)roi)ertY. it may not be representa- 
tive. The clay is suitahh> foi- the manufacture of fire bi-ick, roofing- tih', 
terra cotta, and for any pottery oi- decorative tih' in whicli the l)ulf color 
is not objectionabh". 

No. 201 (p. 69). Calaveras Count \. llelisma. This is a plastic, 
buft'-burning clay from the lone formation. The plasticity is smooth 
and strong, the dry strength is high, and in the dried condition it has 
finger-iuiil hardness, is fine-grained, antl close-textured. The sample 
contains 11.4'/^ of +200-mesh sand. Tiie colors are: dry, 17'"f; wet, 
17"'f ; cones 010 to 04, ll"i; cones 02 and 1, 17''d; cones 3 to 6, 17"b ; 
cones 9 to 13, 17'". Steel hardness and lO'^ absorption are developed 
at cone 04. The fired structure is tough, stony aiul .sound, excei^t at 
cones 11 and 13, where large cracks appear. Vitrification is complete at 
cone 9, above which temperature bloatnig begins, but the softening point 
is cone 28. The maximum total linear shrinkage, plastic basis, is 21.5% 
at cone 9. The clay is suitable for the uuniufacture of face brick. 

No. 252 {\i. y)2). Amador County, lone. Core drill hole No. 57-2, 
Arroyo Seco Grant. Tliis sample i.s similar to No. 245 and 249, in 
class 7, with the important diiil'erences as noted below. The colors are: 
dry, 17"f ; wet, 17"'f ; cone 1, 13"f ; cone 5, 17"'f ; cone 9, 17'"d ; cone 
13, 17""d. Slight blistering is noted at cone 13. The maximum total 
linear shrinkage, plastic basis, is 22.4%, at cone 9. The softening point 
is cone 32-33. 

Ao. ^80 (p. 147). Placer County. Lincoln. Clay Corporation of Cali- 
fornia. See also No. 153 and 146. The plasticity is excellent, the dry 
strength is medium-high, and in the dried condition it is medium-hard, 
close-grained, and fine-textured The bonding strength, with 50% 
(3ttawa sand from — 20 to +30-mesh, is 211 lb. per sq. in. It con- 
tains 11.2% of +200-mesh sand. There is slight effervescence in 
hvdrochloric acid. The colors are: dry, nearly white; wet, 17"'f ; cones 
010 to 04, 7'f ; cones 2 to 5, 7"f ; cones 7 to 13, 21""d. Steel hardness 
is developed at cone 02, and less than 10% absorption at cone 1. The 
fired structure is stony, and is sound up to cone 9. At cones 11 and 
13, a few cracks are noted, and there is slight blistering. The surface 
texture is smooth. The maximum total lineai' shrinkage, plastic basis, 
is 20.3%, at cone 9. The softening point is cone 30-31. The clay is 
used by the Stockton Fire Brick Co. in the manufacture of fire brick 
and refractory cement, aiul is marketed to tile manufacturers and 
others. 



20—54979 



306 



DIVISION OF MINES AND MINING 



TABLE No. 20. 

II. Buff-Burning Clays. 

A. Refi'actory clays, softi'iiing point cone 27 + . 

b. Dense-burning, less than 6''/< apparent porosity between cones 10 and 15. 

7. Mainly medium to high strength, but also including some clays of low strength. 



Clay 






No. 


% S.W. 


% P.w. 


1.3 


12.4 


15.9 


3!t 


14.7 


18.1 


.■iC 


13.1 


10.9 


8U 


17.0 


24.8 


83 


12.8 


17.5 


85 


16.3 


17.7 


101 


16.5 


17.1 


110 


20.3 


20.6 


i:{;i 


22.4 


21.5 


149 


18.6 


18.8 


15.3 


20.7 


21.8 


156 


20.3 


17.1 


204 


17.1 


17.7 


213 


15.5 


23.8 


229 


17.0 


18.4 


230 


15.4 


18.4 


245 


19.6 


17.2 


246 


15.2 


17.2 


247 


18.1 


20.7 


248 


27.3 


16.4 


249 


18.7 


16.8 


253 


20.2 


20.5 


254 


19.6 


21.8 


271 


17.0 


17.5 


274 


19.1 


15.4 



% W.P. 
28.3 
32.8 
24.0 
41.8 
30.3 
3 4.0 
33.6 
40.9 
47.9 
37.4 
42.5 
37.4 
34.8 
39.3 
35.4 
33.8 
36.8 
32.4 
38.8 
43.7 
35.5 
40.7 
41.4 
34.5 
34.5 



D.T.S. 
255 
257 
628 
Erratic 
230* 
245 
355 

200-400 
140 
260 
616 
670 
280 
105 
181 
±419 

O O r 
o o O 

328 

309 
±680 
±395 

204 
±251 

531 

444 



% D.V.S. 
22.4 
25.5 
26.4 
27.1 
22.8 
28.6 
30.0 
34.2 
34.6 
32.5 
33.7 
36.1 
29.9 
24.7 
29.7 
27.4 
34.5 
26.8 
30.4 
48.4 
33.8 
33.3 
32.2 
30.4 
35.1 



% D.L.S. 



7 

7 
8 
8 
7, 
8 
9 
10 
10.4 
9.8 
10.2 
10.8 
9.1 
7.6 
9.1 
8.3 
10.4 
8.2 
9.2 
14.1 
10.2 
10.1 
9.7 
9.2 
13.4 



Soften- 
ing pt. 
in cones 
29-30 
29 
27 
33 
29 

31-32 
30 

32-33 
33 

31-32 
30 

28-29 
27 
31 
32 

32-33 
30-31 
29 
32 

30-31 
30-31 
31-32 
31 

31-32 
30 



* Bonding strength with 50% Ottawa sand ( — 20- + 30-mesh) is 56 lb. per sq. in. 



c. Dense-burning, less than 6% apparent porosity between cones 5 and 10. 



8. Medium to high strength. 



Clay 
No. 
121 
124 
136 
146 
1^7 
1^1 
152 
157 
175 
201 
252 
280 



; S.W. 
27.4 
17.4 
20.9 
19.7 
20.5 
29.5 
26.8 
20.2 
15.4 
23.2 
17.6 
19.5 



% P.W 
20. 
19. 
20. 
19. 
U 
28. 
22. 
22. 
17. 
18. 
21.1 
20.7 



% W.P. 
48.1 
37.0 
41.0 
38.8 
39.2 
37.9 
49.4 
42.3 
.'!2.5 
41.4 
38. 7 
40.2 



D.T.S. 

3 40 
219 
270 
239 
284 
301 
710 
37!t 
369 
89 4 
296 
466* 



% D.V.S. 
45.3 
29.4 
35.4 
34.0 
35.6 
43.4 
43.0 
33.2 
27.5 
40.2 
29.2 
33.1 



% D.L.S. 
13.2 

8.9 
10.6 
10.3 
10.7 
12.8 
12.8 
10.1 

8.3 
11.9 

8.9 
10.0 



Soften- 
ing pt. 
in cones 
33 
32 
31 

31-32 
31 
30 
33 

32-33 
30-31 
28 

32-33 
30-31 



• Bonding strength with 50% Ottawa sand ( — 20- -f 30-mesh) is 211 lb. per sq. in. 

f/c S.W. = Per cent shrinkage water. 

% P.W. = Per cent pore water. 

f/r/W.P = Per cent water of plasticity. 

D.T.S = Dry transverse strength, pounds per square inch, without sand. 

% D.V.S. = Drying shrinkage, per cent dry volume. 

% D.L.S. = Calculated linear drying shrinkage, per cent dry length. 



CLAY RESOURCES AND CERAl^fTC TXDUPTRY 



307 



2 ^ « 



•' « S > 

a * E £ 

P S -2 _2 . 

= -^ -= .r 5 

'c 'E "^ -o ^ 






- -^ at -^ 



z 

Id 


u. 


5 


V. 


2 


_j 


■n 




^ 


« 


< 


l" 






— 


t- 


— . 


hr 


o 


bC 














-f" 


-^ 


^ 


■ — 


















3 


3 






n 


-o 


-O 






I 


g 








Q 


.*. 





f3 «a ' c^ j.-^ 



S 

o 


.^=^' 
" -< 


ktirf t t t < CO WT >C «M 


I ' "^ 




1 1 1 1 . ■ ■ ■ 1 ie4<<f«cO « '^00 ' 


CO 

oo 


••'S 


e^eo • ' • le^cMeo— < 


! 1 -co 

< I ICO 

I I !" 




t I h* c^i »r> '< I o: -^ I 


o 


CO 

c 
o 

O 


^i 


OCICl 'CS'J'CiCOTfC^»0 0'»«-f'C^I-^CC>OW:cDOcOOC^HMCO<;©OOcO(N05COOO — 


t>- 




^i 


«»oh- icoc^O'^'<j«c^u3i««iC^'^oscocn'^o?ocDOOioocooe^o — ooo:D'«j<r>-ooc^ 


•^cpo 'NOc^t^t^fMcitD<r:/--foooo*^iMO^iO-*i^-*o«eow^(M^oc^aiooec 
^c^i^ 'cococi«ccroc-r^c^-^ccc^c^ic^coc^c^eoeoc^ici'«»'coeoeowco-^'^po^ecc^ 


B 

6 




^C1C^t^C:iOOCv«c;OOCCOO-H 




I 1 1 1 1 ICC CiCOO >COO OOi ^COO 


»o 


CM C^l — — -- „ c^ 


■ 1 1 1 1 iCMC — COCMOOO — 1-*"^ 


^.» 


t^cDC^-^-C^OOCOOOO — ic-«»«i-«eD 




• •III iCM*e}4 OCMO'^OCOCOO'^ CM 


g 




?0 •<»' O »r5 CO lO -^ OS CM 05 -H OS 

i t 1 1 » 1 Ci) CM '^ CO CO CO CO CO ■* CO CO ^^ 


c 
o 
O 




coooooo'C^iic«ooc'icoc^Jco5DTt"r-coO(M^r-ooi--'M — »oroooocc— cooot-* 


C5 




— ' 


..^ 


00'^»CW500CCt^OS-^T'«OOCOOOOOiOCO<OCOC^^CvlC4TT'»00*C OO--^ OOOSl^OiO'^fTt*^- 


C0tD^CD00Tf-t<-t'O00O5l^CCO-f«00M'Oh»'a=C^CCCCt^00C00l*<*'C0O^Ci<-'C*«OiC« 






c*:oooc*3C^or*0"^0:c»cooeot* < < 

COOm — CCCOQOCr.iMCOCv CCCICOC^I ! 1 
C4CO— '^"^(M ,— ^^«— .C^JOJ 1 1 


' ' 1 1 ' <CCTfl"-'*t'COOlCMO-«*<OCOCM 

I I I I 1 loO^OOeOCJOOOCMOlCMCM 
iiiiii — CM'-'"— =«. 


CO 
CO 


> 


O r* lO t^ woo -^ C5 ^QO — Oi CDOO CM • I 

C0C0^MC0(M-t<-'fCit^:O'-«O;C»C0 • 1 
^^ ^ -^ ^ CM CV| ^ CO fO <M <M C<1 '- C4 'M • i 


CO ^ CC OOO CM OOCMOOCOCO O 

< CO CO h- CO OS rt* — O CR CO O CM 

I 1 1 1 1 CM I-- CO CO CM CO CO -^ CO CO CO CO 


CO 


o 

c 
o 




ciCMooto<Mcs»oooooiiCt^Oic:c>ose<i---^t*oeococDiooi^oo»cc:OcDOost^Ou: 


,^ 


;1;Op-f?Cl^p»OCOMOCOOOcO(M-f-r3-CCeOCOCM-rt<t^OCOCOCOt^<MTf-^-»i't^OCM^ 


(M 




lOC^J^ooooco»o^^lCOCMco'r)•lOcoc5•^0(^ic^1^ooot:r*otr;c:«^:I:^!^^•r^clOoooo 




CO 

o 




tooo:oo-rt«xiooot~*ooc^icncOTj< 




' 1 - • 1^- Tt '^co «: ^ o -* oi 05 m r^ 

; • J 1 tCICMCM — — ^«CM " 


CO 


cc>ait^o«pcoocoecocO'*^oico 

CMCM<— •MCMC'I'M.— i^^CMCM'— "C^CMCM 




Q0CiCr:C0(Mr^-^Cnrj':0C^)^00OO 




' 1 1 t ■■-J'lCOO'— Oi-n''-fC»C:iOCCoO 

' ' ' 1 >OCO!:OCDiO»0'OOI--;0000 
CM^CieOCMCviCMCCCOCOCMCO 


o 


CJ^O--i2CMI^a;CMt*0(MCMt^-rt«0> 
— — COCM— COW01(NCM^«M — 






CMCMicooe-^CMco^oocMcocoo 

CMCO-HCOCMC-ICM-MCOC-KM— CMCOCO 


or^i^^o<NcotocMooi^oiooo«:i-^icco»(5cc't^ 

XilCtOCJ-r-C^ldiOOlOO— >t^<OOCMCri(MQOOSCOas 
C4CJ(MeiCMCO(M(MCMCO'M'M<MCM<M"CM^ CM^ 




^-rocoO'M-rcoci^-',o-fO:OOCi 


cotc^o3C5;c:coc;00-*c;oa;c^cX) — coco 
r--t*oot--oioC'rfCM— »ra>cc^ic^ioO'— 'ooooocoo»o 

— '^ ^ " — " •— (M — ^ C<l CM -- CI CI (M CO CM CM CI (M C^l 


o 
o 

o 

a 


< 


OCT, (M-ft^OOCMlOOOSCDCOOO-rf 




1 ' t ' p uo O »0 OS CC CM CD Tf »0 CM O CM 

1 ' 1 • ' OS oo CD O CO ICIO t^ r^ CM CO »o 
. . 1 . .CMCMCOCOeOCICMCMCOCOCM^ 




o^cMoo»oco — CMi-*r~».i— lC•lr^ooco•■*> 
cocv?(^^cococococo:0'^^M(^!'^^^coM 




eoiooco-for^oicpoc'jcc-rcoi^o 




0»0 CM O -^ CO »CCM O CO-t» ^ 


00 
CM 


iCCOCOOt^t-iCoOCOCO-f-fiMTfOCS 


I • 1 • 'cooiicr— cioo'XJco-^ooo-f 




-r 
O 
<u 
c: 
o 


< 


w r^ i, .rs c: -M :c oo O c^i r; o OS :c ^ i i 

-f -* ic ^- t-» CO c^i s; ro CO ic r* (.M c^ ift , , 

eocooj-t.cocoecco-rwcoc^co-r'ev5 , , 


■ I I ' 'CM^-^O-^-f'-DOl^CIOOt^ 

cot-^i^QO»c>c-rr'-c-oc'ios 

CO CM CO CO CO CO CO CO CO CO CO ^ 


CO 

CO 
CO 




QO CO ^ »r3 oo O oi O CO >c >0 -^ C: '--M o; ! ! 
ClCO<M»0-^'^'M005'»fOOOOtOOOOO • • 


• •11 lO lOCO — coco CO»C CM COCOCM 


^ 


0Or^CMb-O0t^»«CMd— ooo 


CM 


o 

§ 


wS^ 

" -d 


OOOC0C0':Cif;i0 00^O-f00:0O-1' I 

cococ^-^cofoeo-r-*cocococc-*coco « 


O: -M lOCMOil- O t-CM CO C» O 


■* 


1 1 1 t iCMO;C0!D»C»0i0 00O05-f^ 
' 1 • • I CO CM CO CO CO CO CO CO "^ CO CO CO 


CO 


..» 


CiO-— •Qoi--coiooc^i(Mr^oooii^»nco 




TfCO-^OS*OI^OO. -^t^cDOO ' 

. 1 1 .) ■ (^ Tf CM ;d «: lO -^ OC- -^ O: 00 00 ' 


in 


i-eocM-^-j-cowoJOO^t^iocor^cDoo 


oo 

o 

c 
o 
O 


is"" 
< 


00COOOC000»C00C^I'M;:O''^»r300O 




i 1 1 . ■cDcDeO»-00(-*»^— 'CO'-OOOs ( 

1 1 t 1 i«*a:OO'-CDir5il0OOOSC0CM 1 
1 1 1 1 • CO CM 'Tf CO CO CO CO ■* -^ CO CO CO ' 


CO 


eOCO(M-*<COCCeO'*'rJ«COCOCOCO-*-CO 


mi 


C»li-«-<J*rJiC0CMiOe0OS-^a>t^(3iC0iO ' 




i I I I I^O^iOOSr^-^CMOcDOTt^ 1 
> 1 1 1 icO-^'-<»0»C'*COCDOOOSCD<0 1 


CM 


"CO ^ -+ CMCO" Wt-^CO O CDCM b- U5 , 


o 
o 
u 

5 

O 


.o^: 

'■'-H 


— 0^<Mt^-#<MOO^^<M.-««-^COr* 1 

cM»c:o — t-^'—co — CMTft^w-i^cMu:) I 

cococ-i'^rcococo-^'^corococo-Teo • 




' 1 I • ■COtMCOCOOOcDCOlOCMCMI^t^ ■ 

I 1 1 1 .M^CSOOO^OcDiOOS — OcD-* ■ 
CO CM -r CO CO CO CO CO TT -^ CO CO ' 


o 

CO 




O — iOC^Jt^(N.-iTf-rf"CJOCOiOt-* ' 




! 1 1 ! If-Hoasoot^-^ocMasoooo '< 

'III iCDCMI^ iO!D ^ 1^ lOOO OS »OiO ' 


o 


»— CO^H-^ti— .C^lOOOOCOOiOCM^DCO 1 


> 




'-HrOiCOOCOOOO^CO^iC»CO'— CMCO-^'rJ''rr--t*-rt'»/3lOt^t^C-lCMCO'rrM'»ClOlOt--OiOOO 
_ — — ««„C^, C^ICM<MC1MCM(MWCMCM<NCM — — — ^-^^-S-^-«C^wS 


Class 


No._. 


r^ 






00 





+ 



c 
o 



O 



+ 



o 



II 






s. 



II 

> 

6? 



308 



DIVISION OF !\nNES AND MINING 



A lisc)i-]il idii ami linear .shi'iiikagc cui'vcs for clays of class 



010 08 06 O^OZ I 3 S 7 9 II 15 15- 



S 
I 

tt: 

S 

-J 
»^ 

•« 

^" 

I 

I 

*9 



20 
10 

20 
10 

o 

20 
10 

20 
10 














No 


13 


















N 


^ 


— 


-^ 
















— • 




_s 


_ » 


.- 


-- 


-- 


-- 


-- 


>^ 










.A 


No 


39 




















V 


^ 


— 




^ 








-■*■ 


w * 


-• • 




s 




-- 


-- 


-- 


-- 


— 


's 












No 


56 














_ 






A. 
























s. 


***■ 


~'^ 


" 


rr 


=^ 


►-^ 










V 


A 


No 


60 




















S 


\ 


• • 


w * 


-"■ 


~ " 






-- 


-- 


-- 


-- 


•■ ^ 




^ 




^ 


^^ 







ft: 



//fAT TREATneNTlNCOfiES. 



CIO Oaob Cf OZ I 3 S 7 S II 13 IS" 

20 
10 


20 
10 

o 

20 
10 

20 
10 

HEAT TRFATHFNT IN CONES 



_ 










No, 


83 


















\ 


-^ 


»** 


— 






.. 










_s 


^^ 




— 




-^ 










A 




No 


85 
















^^ 




"V 


^ 




^ 


=« 




«•* 










_S_ 


^' 


— 






S 










A 




No 


10) 




















— 






•V 


^^ 












S 


.. 


M » 


— 


— 


— 




*<. 


s 


— 




— 


< 




No 


II 





















S 


Si- 


., 


.* 


— - 


-- 


— 


^H, 




^_ 


-- 


,s. 


^^ 


"S 




"" 


— 




_ 


^ 



or 



OK) 08 Ob Of OZ I 3 5 7 S II 15 IS- 



I 
I 
I 



20 

10 

O 

20 

/O 
O 
20 
10 
O 
20 
10 

O 





■~" 


A 


S 


\. 


No. 


13 


3 


















\ 


V 


... 


... 


-- 


... 


-, 


".^ 


.- 





_S_ 


-- 


.-' 


' V 


— 


— 


- 


^ 


/ 


^ 






A 






No. 


H 


9 
















\ 


N 














k 


n* 




.S 


^ 


^^ 


-- 


'• - 


^ 


— 




^ 


/ 




— 


^ 


Sn- 




No 


15 


3 


















\ 




__ 


»> 




^ 


^ ^ 




„ 


_. 


_S. 


^•l* 


-- 


-' 






^ 


\ 


■*-* 














No 


15 


6 














A 


V 


^«j 
















r* 


__ 


JS. 


^* 




^ 


==^ 


Z^ 


. 


"*^ 


^ 





(XiOBObOfOll 3 5 7 9 II 15 /T 



/^£AT TREATMENT IN CONES 




HEAT TREATMENT IN CONES. 



CLAY RESOURCES AND CERAMIC INDUSTRY 



309 



Absorption and linear shrinkase curves for clays of class 7. 
010 08 06 Of OZ I 3 5 7 S II 13 ir 




HEfiCT JREfirnENT INC0NE5. 



i 

tt: 

-J 



OlOOSOb m OZ I 3 5 7 9 II 15 /r 

20 

10 

o 

20 
10 

a 

20 
10 

o 
20 

to 

° HE A T TREAinEN T IN CONES. 













No 


25 


3 






1 


— 












^ 


Srf' 






^— 












'i 


^S 


— 
















No 


Z5 


4- 




















\ 


^^ 


— 


— 


.S 


— 














r' 


\ 






^ 










- 










No 


27 


1 














""^ 


^ 


V 


















_^ 


-.- 


_s 


-- 


*"• 


r*. 






V. 














No 


27 


4 










— 


— 






A 


. 




_ 


•V 












„ 


— 


s 


— 


— - 




^ 


^ 





310 



DIVISION OP MINES AND MINING 




m 



5 ^ a 5 o ^ S o 



o 

u 
o 

m 

> 
;-< 
3 
o 

a> 

Ul 



m 
u 

a 



o 



b. 



en 



S ^ 



o 










( 
















/ 


\ 




• 


\ 




1 


V 










\ 
























1 

1 




t- 




/ 








M 






t^ 


1 

1 




i 


t 

1 


\ 


n 




/ 


\n 






lo 


1 

1 


1 


6 

Z 


t 


/ 


^ 




/ 


Z 


1 
1 


/ 


c5 

Z 


1 








( 




i 






• 

« 


/ 




\ 

\ 


/ 




/ 


\ 

\ 




/ 


\ 


> 


X^ 


V 




/ 


* 


J 


/ 


\ 


/ 


/ 


\ 
\ 


/ 




1 

1 


/ 


r 


\ 


< 




lo'i 


i 




< 


<l 




w\ 


-i 




w, 








J 




1 






1 

1 












:\ 




1 
._ 1. 






1 









^ 



5 o 









I 

5 



a 
u 

o 
m 

< 



CTl 

in 

99 



§ 



Q O O 






S o ^ o o 

















3 

1 


\ 


/ 


'r-\ 










1 

\ 






1 
1 














/ 




1 
1 


/ 




1 

1 


/ 












/ 




1 

\ 


1 




I 


/ 








_ 




J 


+ 


t 
1 


/ 


a? 




/ 


vo 


1 


/ 


OJ 


V 


/ 


M 


1 


/ 


r? 




f 


^ 


1 


I 


o 

z 


/ 


\ 


^ 




i 


z 


/ 


V 


Z 






J 


/ 


» 


/ 


\ 
\ 




/ 


\ 
\ 




1 


T 


V 




«! 


"v 


/ 


^\ 


<j 




w' 


< 


/ 


cri^ 


/ 




) 

\ 


1 




1 

1 








1 




1 


./ 




\ 

1 


/ 




t 
1 






i 


/ 




1 


/ 




t 
\ 


1 


1 






i 






i 
1 






I 



SI^VffXW'39^MNmSDNIilU mSHllX I'M NO/ldmSQn 



(LAY RESOI'RCES AND fERA:viir IXDITSTKY ''ill 

ll-B. Non-refractory Clays, Softening Point Cone 27 — . 

a. Oi'E.\-HrKxix(;. Xor liKLow 6'/( Aim'Akkxt Porositv P.elow 

Cone 10. 

9. INIedium to IIii>:li Streiij^th. 

Xo. 19 (p. 16:1). Kiversidp (\)nnty. Albcrliill V. & V. Co. "Yellow 
Strippin<ir. " This is a yello-\visli, saiuly (.'lay that occurs as overburden 
on parts of the i)roi)('rty. It contains 28.2% of --|-200-mesh sand, and 
has sufficient plasticity and stren<>th to i)enuit its use in a superior 
grade of coiiunon l)i-ick, which is marketed undei- the name of "Diamond 
Brand." The dry stivngth is medin)u-lii<ih, and the dried clay is hard, 
■with a medium j^rain and oi)en te.xture. The colors are: dry, 15''d; 
wet, 15"; cones 010 to cone M, 7'd ; cone 5, 9'f ; cones 7 to 9, ll'f ; cone 
11, 15'f ; and cone 1-3, 15'b. Fin<?er-nail hardness develops below cone 
010, and steel liardness at cone 11. A few small craclvs developed in 
the test piece that was fired to cone 13, but all other test pieces were 
sound. The total linear shrinka<2:e, jilastic basis, is 8.4%, at cone 13. 
The softenin<r ])oint is cone 23. The best firin<r ranji-e is from cone 010 
to cone 11. Tlie clay seems entirely suited for makinp; bufP and pink 
face brick. It does not vitrify at sufficiently low temjieratures to be 
suitable as the sole in<;redient of bodies with low porosity. 

No. 25 ()). 163). Riverside County. Alberhill C. k C. Co. "West 
Tunnel Blue." See No. 94 and 9."). This is a pink and butf -burning 
sewer-])ipe clay having a fail- plasticity and medium dry strength. It 
contains 18.8% of +200-mesh sand. In the dry state it luis a medium 
grain and open texture. The colors are: dry, 23'''''f; wet, 23"'"d ; 
cones 010 to 04, 17"f ; cones 02 to 5, 15''d ; cones 7 to 11, 15''b; cone 13, 
Ty"". It is practically red-burning at cone 13, but is best classed as a 
buff-burning clay. Finger-nail hai-dness is developed at cone 010, and 
steel hardness at cone 1. Vitrification is well advanced at cone 9. The 
total linear shrinkage, plastic basis, at cone 13, is 19.3%. The softening 
point is cone 16. The best firiiig range is from cone 1 to cone 13. The 
])rincii)al value of this clay lies in its vitrification i-ange and tempera- 
ture, coupled with good fired strength. 

No. 36 (p. 20). San Diego County. Card iff. California Clay 
Products Co. This is a Pleistocene ( ?) fireclay, similar to samples No. 33 
and 34 in class 6, but with less iron and a higher percentage of fluxes, 
]irobably feldspars. It contains 44.4% of -|-200-mesh sand. The 
l)lasticity, and the dry and fii-ed properties are closer to sample No. 33 
than to No. 34, but the colors are uniformly of lighter tones and the 
fired porosities are greater, though the shriid^age is practically the 
same. The total linear shrinkage, ])lastic basis, at cone 13, is 8.2%. 
The softening point is cone 26. The best firing range is from cone 1 to 
over cone 13. 

No. !H (ni<] !>.') (\). M\). Kivcrside {'()iint\. Alberhill. (1.. McB. & 
Co. No. 94 is the "West Blue" and No. 95 is the "Select West Blue" 
clav. These two samples should be compare(_l with No. 25, the "West 
Tunnel Blue" of the Alberhill C. & C. Co., and not with their "West 
Blue" (No. 23, class 5) and "Select West Blue" (No. 16, class 10) 
varieties. No important differences betAveen No. 94 and 95 were dis- 



312 DR'^ISION OF MINES AXD MIXIXO 

closed by the testiiifr, but they both have a hipher proportion of sand 
and a lower percentage of iron than No. 25, Avhicli results in a largre 
difference in the ceramic properties and uses of No. 9-t and 95, com])ared 
with No. 25. No. 94 contains 24.2^f, and No. 95 contains 27.6'/; of 
+200-niesh sand, compared to 18.8'/f for No. 25. The plasticity of 
No. 94 and 95 is good, the dry strength is medium, and in the dried 
state they are soft, medium-grained and open-textured. The colors 
are: dr^', 17""f ; wet, neutral gray; cones 010 to 02, l."]'"d; cones 1 to 
13, 13""d. Abundant jiarticles of ferro-magnesian minerals give a 
pleasing granitic texture to the test pieces fired above cone 1. Finger- 
nail hardness ai)]iears below cone 010. and steel hardness at cone 1. 
Absorptions under 10*^^ are obtained at cone 3. Bloating is pronounced 
at cone 11, especially when a reducing flame is used. No. 95 has lower 
shrinkage and lower absorption at cone 9 than No. 94. The maximum 
total linear shrinkage, plastic basis, is at cone 9. and is 11.7/^ for No. 
94, and 10.5 'y for No. 95. The softening points are cones 17 and 18, 
respectively. The best firing range is from cone 1 to cone 9. No. 94 is 
used in tile bodies, and No. 95 in terra cotta bodies. 

Ao. 5.9 (p. 171). Riverside County. G., McB. & Co. "Tile Clay." 
This is a red and tan-burning plastic clay that is used for the manu- 
facture of roofing tile, face brick, and similar products. There is slight 
effervescence in hydrochloric acid. It contains 30.89c of -)-200-mesh 
quartz-mica sand. The plasticity is excellent, the dry strength is 
medium high, and in the dried condition it is medium hard, medium- 
grained, and open-textured. The colors are: dry, 13""d; wet, 17""; 
cones 010 to 02, 7"b ; cone 1, ll"b; cones 3 to 11, 13"b; cone 13, 15". 
Mottling from the presence of ferro-magnesian minerals is pronounced 
above cone 5, giving pleasing textural effects. Finger-nail hardness is 
developed below cone 010, and steel hardness develops at cone 5. 
Absorjitions below 107c are not obtained until cone 11 is reached. 
The fired structure is sound and stony and the texture is rough. The 
total linear shrinkage, plastic basis, at cone 13, is 11.99^ . The softening 
point is cone 26-27. The best firing range is from cone 02 to cone 9. 

No. 114 (p. 90). San Bernardino County. Near Rosamond. Titus 
deposit. This is a buff-burning clay with fair plasticity, medium dry 
strength, and a medium hard, medium-grained, dried condition. It 
has not been produced steadily, but tests have been made by various 
clay manufacturers. The colors are: dry, grayish white; wet, 23"'"f; 
cones 010 to 3, 17"f ; cones 5 to 9, 17'"f ; cones il and 13, grayi.sh white. 
Finger-nail hardness is developed below cone 010. and steel hardness 
appears at cone 1. The fired structure is sound, homogeneous, stony, 
and without warp. The surface texture is slightly rough. Above cone 
11, scattered iron specks become noticeable. Absorptions below 10/^ 
are obtained at cone 9. The total linear shrinkage, plastic basis, is 
6.9%, at cone 13. The softening point is cone 17-18. The clay might 
be useful in stoneware, vitrified floor tile, and similar mixtures, 
altliougii for the highest purposes, wasiiing would be necessary to 
remove the non-plastic coloring impurities. 

No. 13'i (p. 58). Amador County. lone (Clarksona). N. Clark and 
Sons. "Dosch Stripping." This is a sandy yellow-burning clay with 
good plasticity and medium-high dry strength. It contains 18.0% of 



CLAY RESOURCES AND CERAMIC INDUSTRY ^H Tj 

-|-2()()-HiP.sh sand. In the dried condition it is medinm hard, fine- 
•rraincd, and close-textured. The colors are: dry, lo"d; wet, 15"1) ; 
cones 010 to f), 9"d ; cone 7, 19"b. .Steel hardness (lev(dops at cone 02, 
and less than 109' absorption at cone >]. Tlie fired structure is sound, 
g:rannlar and roup^h-textured. A vesicular structure develops above 
cone 7. Tlie maximuni total linear shrinkaofe, plastic basis, is 15.1% 
at cone 7. Tliis niatci'ijd is used in sewer-])i])(» mixes. 

Xo. 168 (p. 1;)6). Nevada County. Cliica^o Pai-k. Beaser Rancli. 
Til is is a pink-burninj; clay from near the surface of an undeveloped 
deposit. The plasticity is smooth, but weak, the dry strengtli is medium, 
and in the di-ied condition it is medium hard, fine-»rained, and close- 
textured. The colors are: dry, 17"'f; wet, 17"'d: cones 010 to 06, 
l.yf; cones 04 and 02, 15'd; cone 1, Wh. The fired colors are ochra- 
ceous salmons and butTs, which are unusual. No scumminf? or efflo- 
rescence was noted. Steel hardness is develo])ed at cone 02. The fired 
structure is .sound, aiul stony, and the surface texture is exceptionally 
smooth. The total linear shrinka<>'e, ])lastic l)asis, is 8.6% at cone 1. 
The clay could be used locally for common. brick, and might be u.sed to 
make an attractive, though unusual, face brick. 

No. 169 {]). VAH). Nevada County. Pearldale. Sonntag Ranch. This 
is a buff-burning clay from a surface exposure of an undeveloped 
deposit. The plasticity is fairly smooth and strong, the dry strength 
is medium, and in the dried condition it is soft, medium grained, and 
open-textured. The colors are: drv, 17"f; wet, 17"d ; cones 010 and 
08, ll'f; cone 06, i:rf ; cones 04 and 02, 15'f ; cones 1 to 5, 17'f ; cone 
7. 17"d; cones 9 to 18, 17"'b, but with a distinctly mottled appearance. 
Some interesting color etTects for floor tile and face brick can be pro- 
duced with this clay. Steel hardness is developed at cone 1. Less than 
10% absorption appears at cone 7. Slight bloating is apparent from 
the shrinkage and porosity data at cones 11 and 13, but no loss of shape 
was noted. The fired structure is sound and stony, and the surface 
texture is slightly rough. The maximum total linear shrinkage, plastic 
basis, is 11.1/^ , at cone 9. The softening point is cone 19-20. The best 
firing range is from cone 1 to cone 9. 

Xo. 173 ( )). 2;>r)). Yuba County. Smartsville. J. P. Dempsey Ranch. 
Kaolin itic material from a copper prospect in volcanic rocks. It was 
not possible to secure a sample entirely free from limonite. The plas- 
ticity is fair, the dry strengtli is medium, and in the dried condition, it 
has finger-iuul hardness, is medium grained, and open-textured. A 
high percentage of non-pla,stic matter is present. The colors are: dry, 
yellowish wliite; wet, 17'"f ; cone 010, 7"b; fading progressively with 
increasing firing temperatures to 13'"d at cone 5. Green scumming is 
pronounced. Steel hardness is developed at cone 04. The fired struc- 
ture is sound, and fine-granular, except at cone 6, where light super- 
ficial hair-cracks appear. The surface texture is slightly rough. The 
total linear shrinkage, plastic basis, at cone 9, is 19.1%. 

Xo. 255 {\). r)2). Amador County. Tone. Core drill hole No. 57-5, 
Arroyo Seco CI rant. This is similar to No. 254 in class 7, but fires to 
darker colors. The plasticity is good, the dry strength is medium, and 
in the dried condition it is medium hard, fine-grained and open- 
textured. There is slight effervescence in hvdrochloric acid. The colors 



314 DIVISION OF MINES AND MINING 

are: dry, i)"d; wet, 9"b; cone 1, 9"d; cone 5, 15"d ; cone 9, 17"b; cone 
18, 15"i. Steel hardness is developed below cone 1, and less than 10% 
absorption between cone 1 and cone 5. The fired structure is sound and 
stony, and the surface texture is smooth. No blistering w^as noted at 
cone 13. The total linear shrinkage, plastic basis, at cone 13, is 21.6%. 
The softening point is cone 26. This is a good clay for face brick, 
roofing tile, and similar products. 

No. 283-A and B (p. 232). Tulare County. Dueor. W. A. Sears 
deposit. See also No 284, class 10, and 285, class 5 These are samples 
of impure kaolin, aiul have fair plasticity and medium dry strength. 
The dry condition is medium-liard, fine-grained, and open-textured. 
The colors of No. 283-A are: dry, nearly white; wet, 15'f ; cones 010 
to 3, 17"d; cones 5 and 7. 17^1;' cone 9,'l5'd; cones 11 and 13, 13'd. 
The colors of No. 283-B are: drv, gravish white; wet, 21""f; cones 
010 to 02, 17""f; cones 010 to 5, 21'"f; cones 7 to 13, 17"d. The 
colors are rather disagreeable yellowish buffs, and are irregular. Yel- 
low scumming is very pronounced. Steel hardness is not developed 
up to cone 13, the upper temperature limit studied. The fired struc- 
ture is sound, and there is no evidence of vitrification up to cone 13. 
The total linear shrinkage, ])lastic basis, at cone 13, is 10.7% for No. 
283-A, and 9.7%, for No. 283-B. The softening point of No. 283-A 
is cone 26-27. Further studies are needed before the possible uses of 
these clays can be predicted. 

10. Low Strength. 

No. 16 (p.WS). Riverside County. Alberhill C. & C. Co. ''Select 
West Blue." See also No. 23 in class 5. This is a plastic, buff-burning 
clay that has a wide vitrification range above cone 7, and is used for 
face brick and pottery. It contains 22.6% of 4-200-mesh sand, high 
in ferro-magnesian minerals, which results in a pleasing granitic texture 
when fired above cone 7. The plasticity is fair, the dry strength is low, 
and the clav is soft and friable in tlie dry state. The colors are : drj^ 
15'""f ; Avet, 15'""b ; cones 010 to 02, 17''f ; cones 1 to 5, 17'"f ; cones 
7 to 13, 17""f, with a granitic texture. Finger-nail hardness is 
developed at cone 06, steel hardness at cone 02, and bloating begins at 
cone 13. The total maximum linear shrinkage, plastic basis, is 14.0%, 
at cone 11. The softening point is cone 18. The best firing range is 
from cone 02 to cone 11. 

No. 55 (p. 195). San Bernardino County.. 4.2 m. N.E. of Bryman. 
Gladding, McBean and Co. This is a vitrifying clay of value in 
face-brick manufacture. It has poor plasticity, low dry strength, and a 
soft, oi)en, dry condition. A large proportion of non-plastic matter is 
present which is high in iron, and results in a pleasing granitic texture 
when fired. The ])ercentage remaining on 20()-m('sh is 48.6. The colors 
are: dry, 7"f ; wet, 7"d ; cones 010 to 04. 7"f, cones 02 to 5, 9'"d ; cones 
7 to 11*, 17""d; cone 13, 15""'(1. Finger-nail hardness is obtained 
below cone 010, and steel hardness develops at cone 1. Absori)tions 
below 10% are obtained at cone 3 oi- above, and bloating begins above 
cone 11. The maximum total linear shrinkage, plastic basis, is 9.5%, at 
cone 11. The softening point is cone 18. The best firing range is from 
cone 02 to cone 11. 



CLAY RESOURCES AND CERAMIC INDUSTRY 315 

No. 8:i (p. 174). Riverside County. Albeiiiill. L. A. B. Co. "Clay 
Shale." This is a sandy, buff-burning: clay shale, with weak plasticity 
and incdiuin low streu^Hi. It effei-vcsccs sli<:li11y in liydroehloric acid. 
In the dried condition it is soft, medium-grained and open-textured. 
The colors are: dry, 17''d; wet, 17"; cones 010 to 3, 5'f ; cones 5 to 11, 
5)'f; cone 13. 17'f. Troii sjjecks are numerous. Finger-nail hardness 
develops below cone 010. but steel hai-diiess is l)ar('ly attained at cone 13, 
at Avhicli point bloating begins. The fired structure is sound, granular, 
and open. The maximum total linear firing shrinkage, plastic basis, is 
3.5%, at cone 11, nearly all of wiiich takes ])lace during drying. The 
softening i)oint i.s cone 23-20. The best firing range is from cone 010 to 
cone 11. The clay may be used with more i)lastic clays as an ingredient 
of face brick mixtures, if the mottled texture is not objectionable. 

No. 88. (Dei)osit not deseril)C(l.) Riverside County. Hudson 
Ranch, near Elsinore. Tliis is an imi)ure silica sand, mixed with 
enough clay to im])art weak plasticity to the mass. The dry strength is 
medium low, and in the dried condition it i.s coarse, open, and friable. 
The colors are: dry, 21""f ; wet, 17""f ; fired, from cone 010 to cone 11, 
grayish-white, with black specks above cone 7. Steel hardness is devel- 
oped at c(me 11. The fired structure is coarse-grained, and weak. 
Enough fluxes are present to cause fusion to begin at cone 9. The total 
linear shrinkage, plastic basis, at cone 9, is 8.3%. The material has 
little ceramic value. 

No. Ill (p. 178). Riverside County. Alberliiil. P. C. P. Co. "Lower 
Douglas." This is a pink-burning clay containing 28.6% of +200- 
mesh sand, but nevertheless i)()ssessing good jilasticity, and a medium 
low dry strength. The dried condition is soft, medium-grained, and 
open-textured. The colors are: drv, 17"f; wet, 15"d; cones 010 to 1, 
9"f ; cone 3, 15" f ; cones 5 to 9, 13'"f ; cones 11 and 13, 17""f . Above 
cone 5. the clay is strongly mottled with iron specks, resulting in a 
pleasing fine-granitic texture. Finger-nail hardness appears below 
cone 010, and steel hardness at cone 1. The fired structure is sound and 
fine-granular. Slight bloating begins at cone 11. Absori)tions below 
10% are obtained at cone 5 or above. The maximum total linear shrink- 
age, plastic basis, is 12.4%, at cone 9. The softejiing point is cone 
19-20. The clay is useful in terra cotta, face brick, and faience tile 
bodies. 

No. 167 (p. ISA). Nevada County. Wolf. Coe property. Pine Hill 
:\rine. See also Xo. 159 and 160 in class 1, and 166 in class 11. This is 
similar to No. 160, but contains more iron. The plasticity is weak, the 
dry strength is low, and in the dried condition it is soft, fragile, fine- 
grained, and open-textured. The colors are: dry, 7"b ; wet, 9'b; cones 
010 to 3, 7"b; cones 5 to 9, 7"d ; cones 11 and 13, 17"'d. Finger-nail 
liardness is developed at cone 010, and steel hardness at cone 11. Less 
than 10% absorption is obtained at cone 13. The fired structure is 
sound, and below cone 11, is fine-granulai". Above cone 11, it is stony. 
The total linear shrinkagf. ])laslic basis, at eone 13, is 13.6^1,. The 
sofi cuing [>oiut is cone 23. 

No. 170 (p. 136). Nevada County. Banner Mountain road. This is 
an impure, sandy, i)ink-])urning clay with weak plasticity, and medium- 
low dry strength. In the dried condition it is medium-hard, coarse- 



316 DIVISION OF MINES AND MINING 

grained, and open-textured. The colors are: dry, 17"d ; wet, 17" b; 
cones 010 to 06, 13"b ; cones 04 to 1, 13"d. Steel hardnes.s is develoi)ed 
at cone 02. The fired structure is sound, granular, open-textured, and 
the surface texture is smootli. Tlie total linear shrinkage. ])lastic basis, 
is 4.8%, at cone 3. It could be used for common brick, but the plasticity 
is barel.y sufificient. 

No. 238 (p. 70). Calaveras County. Campo Seco. This is an nnpure 
sericite schist that is said to have been used as a refractory clay in the 
former smelter of the Penn Mining Co. The jilasticity is weak, the dry 
strength is low, and in the dried condition it is very soft and friable. 
The colors are : dry and wet, grayish white ; cone 010, 17"f ; cones 06 
to 1, 17"d ; cones 5 and 9, 2V'"i. Steel hardness is developed at cone 
02, and less than 10% absorption at cone 5. A vesicular structure 
developed at cone 9. The maximum total linear shrinkage, ])lastic 
basis, is 9.3%, at cone 5. The material is of doubtful value in ceramics. 

No. 269. Inyo County. American Silica Co. "Death Valley Super- 
fine." This is a very fine-grained, sandy material, with sufficient clay 
to give a short and s])ongy plasticity to the nuiss. There is con- 
siderable effervescence in hydrochloric acid. The dry strength is 
medium Ioav, and in the dried condition it is hard, and has a fine sandy 
texture. The colors are : dry, 17'"d ; wet, 17'"b ; cones 010 to 06, 15"f ; 
cones 04 to 1, whiter than 17"; cone 3, 17"d. Steel hardness is devel- 
oi)ed at cone 3. The fired structure is sound and fine-granular. The 
total linear shrinkage, plastic basis, is 26.6%, at cone 3. The softening 
point w^as not determined. 

No. 284 (p. 232). Tulare County. Ducor. W. A. Sears deposit. 
See also No. 285, class 5. and 283-A and B. class 9. This is an impure 
kaolin, having weak plasticity, low dry strength, and a medium-hard, 
coarse-grained, open texture in the dry condition. It was only fired to 
four cone numbers. The colors are: dry, 15"d; wet, 17"; cones 1, 5, 9 
and 13, 15". The fired colors are rather unsatisfactory yellows for 
most ceramic jiroducts. The fired structure is weak and coarse-granu- 
lar. The total linear shrinkage, plastic basis, is 6.4%. The softening 
point was not determined. This is the least satisfactory of the sam- 
ples tested from this de])osit. Yellow scumming is jironounced. 

b. Dense-Burning, Less Than 6% Apparp:nt Porosity Below 

Cone 10. 

11. Low Strength. 

No. 166 (p. rm. Nevada County. Wolf. Coe property. Pine Hill 
Mine. See also No. 159 and 160 in class 1 and 167 in class 10. This is 
similar to No. 159, but contains a higher jiroportion of fluxes and color- 
ing matter. The residue on 200-mesh is 4.6%. The plasticity is smooth, 
and moderately strong, the dry strength is medium-low, and in the dried 
condition it is medium-hard, fine-grained and close-textured. The 
colors are : dry, 13"f ; wet, 9"d ; cones 010 to 06, 7"f ; cones 04 to 3, 5"f ; 
cones 5 and 7, 5""f ; cone 9, ]3""f. Plasticity is not destroyed until 
cone 06 is reached, but steel hardness is developed at cone 02. Less 
than lO'^c absorption api)ears at cone 02, and a vesicular structure is 
developed above cone 3. The fired structure, from cone 02 to cone 3, 



CLAY RESOURCES AXD CERAMIC INDUSTRY 



317 



is soniu], and stony, with a smooth surface texture, 
total linear shriiii\a;^('. phistic basis, is l.l.S';, at eone '^. 
|)oiiit is cone 1:5. Tlie ehiy nii^dit Wud some use as a vit 
hurt', eream, or i)ink bodies burned between the limits 
eone 8. 

TABLE No. 22. 
M. Buff-Burning Clays. 
B. Non -refractory clay.s, .softening point cone 27- 



Tlie maximum 

The soften iiig 

rifyino ao-ent in 

of eone 02 and 





a. Open- 


l)nrning, not 


below 6'/f 


apparent 


porosity lielow 


cone 10. 








;i. 


Medium to 


high strength. 




















Soften- 


('lav 














ing pt. 


No! 


Tc S.W. 


c/c P.W. 


</( W.P. 


D.T.S'. 


% D.V.S. 


% D.L.S. 


in cones 


ly 


11. u 


12.2 


23.2 


463 


21.9 


6.8 


23 


25 


19.3 


18.9 


38.2 


3 88 


34.0 


10.3 


16 


36 


11.8 


19.2 


31.0 


566 


19.9 


6.3 


26 


it4 


9.1 


13.3 


22.4 


207 


17.7 


5.6 


17 


95 


7.3 


12.3 


19.6 


241 


14.7 


4.7 


18 


it 9 


12.5 


14.2 


26.7 


538 


23.7 


7.4 


26-27 


114 


8.3 


13.9 


22.2 


231 


15.6 


5.0 


17-18 


i:55 


15.7 


14.3 


30.0 


437 


29.1 


8.8 




1G8 


9.0 


16.7 


25.7 


315 


16.1 


5.1 




1G9 


8.3 


15.1 


23.4 


246 


15.5 


5.0 


19-20 


173 


20.0 


21.3 


41.3 


391 


33.0 


10.0 




255 


20.6 


21.0 


41.6 


238 


35.2 


10.6 


26 


283 A 


9.3 


34.2 


43.5 


3 47 


11.7 


3.7 


26-27 


283 B 


11.2 


15.7 


26.9 

10. Low 


369 
strength 


19.9 


6.3 


Soften- 


Clay 
No. 














ing pt. 


% S.W. 


% P.W. 


% W.P. 


D.T.S. 


% D.V.S. 


% D.L.S. 


in cones 


16 


9.3 


17.9 


27.2 


88 


16.7 


5.3 


18 


55 


3.9 


15.7 


19.6 


97 


7.3 


2.4 


18 


82 


6.3 


20.6 


26.9 


129 


10.5 


3.3 


23-26 


88 


2.8 


16.9 


19.7 


175 


4.6 


1.5 




1 1 1 


9.9 


16.3 


26.2 


165 


18.4 


5.8 


19-20 


HIT 


8.8 


21.5 


30.3 


62 


14.5 


4.7 


23 


170 


5.3 


19.5 


24.8 


105 


9.1 


2.9 




238 


4.3 


16.8 


21.1 


38 


7.8 


2.5 




269 


31.5 


36.8 


68.3 


166 


39.8 


11.9 




284 


5.0 


18.7 


23.7 


80 


8.6 


2.8 





Clay 
No. 

166 



Dense-burning, less tlian 6% apparent porosity below cone 10. 
11. Low strength. 



% S.W. 
11.5 



% P.W. 
24.1 



% W.P. 
35.6 



D.T.S'. 
117 



<7r D.V.S. 
18.8 



% S.W. 
% P.W. 
% W.P. 
D.T.S. 
% D.V.S. 
% D.L.S. 



% D.L.S. 
5.9 



Soften- 
ing pt. 
in cones 
13 



=: Per cent shrinkage water. 
= Per cent pore water. 

— Per cent water of plasticity. .^, ^ j 
= Dry transverse strength, pounds per square inch, without sand. 

— Drving shrinkage, per cent dry voIum«. 

— Calculated linear drying shrinkage, per cent diy length. 



318 



DIVISION OF MINES AND MINING 









O 






w 
























1 


ft 
















o 














(M 






Ct 










D 














c 


^ 






>. 








o 


>, 






























c 


P 






c 








o 


O 






O, 






>. 


a 


c 










e*5 

n 


o 

a> 

c 


'a 




bl: 




a 
o. 


j:2 
bC 


Z 


E 


o 


rt 


_c 


Ol 




V} 


UJ 

-1 

OQ 

< 


OQ 
it: 

3 






s 

3 


o 

1-J 


C3 


is 

o 


1- 


ffi 


>. 


o 


-a 


o 




•~^ 




■ 


o 


^ 


?; 




c/j 






— 


u 


.^ 






OJ 








C3 




Ol 




- 





m 



O 
O 

O 


^•;; 


!!!!!! 1 1 1 1 !!! 1 






,^-^^ 

>■ 


;;;;;;;;;;;;;; ; I '. I ! I ! 1 I 1 




a; 

5 
O 


< 


O 00 =D ■— ' iC OO ■^ 1 1 05 'lOOO 
(>» CVKM^.— .— ' <« . COM 


coo CD 1 cnTj« 1 . 1 — 

lO O I— > kO t^ ' ' ' — 

— — CO ' — ' ■ 'CO 




< 


CD Ci CD -^ t^ lO «D ' 1 -"J- '-J-O^ 

« 1 ^ ' ' ^ ' CC CI ^ 


CI O iC •-^ Oi 1 ' • ^ 
I-^ — — - C- »0 ' 1 "— 

— 1 ; ^' ; : ;- 




o 




O •* <M CC »0 Oi OJ 1 'b- ' lOb- 
CDCOC^OOOC:!-- i 'O i >cCr- 

M ^ CO c^ •-" i-H .-1 t ' r^ i .eoc^ 


coco CD C5 CO O ' 1 ' 

OJ Ci ^- — CO -^ ' 1 ' 
CO — •-"C4 ' I ' 






OO h* ^ lO 00 '-• CO ' "OO • '(NC^ 

TfiOcDC040-!fr~- « "CD 1 -cs^^ 


OO '^ 00 CI 00 CO ' ' ' 

iccsooo c; w ' ' 1 

CI CJ — Ci 1 ■ 1 




g 


••'^ 


|-^OOt^OcD(MC<l 1 'lOCO'^tiOO 
CD 00 O) O X) CD C: ' ' O OC ^ -,D CT. 


»0 l^ ^ CO O O ICO 'CD 

oocir— di— 'U5 It-' 'CI 

CO — — CO 1 'CO 


CO 




(M CC »-« O t^ CO r* 1 'l>-COCO(Mt- 

-^eocooit^'— CD ■ ■Qocr.cioo 

Csl ^ ^ ^ ■ , ^ c-1 CC'.^ — 


4C CD CD '^J* '^t^ r>. >o 1 -T« 

U7CT50 cr. O^ -CI icn 

CS] — — CI — . — , 


CI 

1 


1^ 

o 

O 




t^OOCS-Tf-nC^cDiM iCOtD iocD 


-+* CI CO eg C- 00 ' ' 1 


CO 

o 


CD;Otf5.— .OOOOOCl iCsiCO it-^OO 
(N M CO " M M ^ 1 ^ CI 1 CO C) 


00 CO I - r- CI t^ ' ' ' 

— CO tN ^ CO ' ' ' 




»0 CD •* ^ CD -* CD O it^OO 't— CD 


'^J* C» Oi -^ CO CI 1 ' ' 


CO 
CO 


CO CO ■* 00 t^ Ol CD •-< ' CD CD ' CI O 


UOCO O iJOOO Oi ' ' 1 
CM-_,__(_- , . . 


*r5 

c 
o 


< 


C^ CO Cft CO OO Tj* (N t- 'OOTfCOi-HO 


CQCIOOC^C^— 1 CR 1 -'if 


CO 


t^ CD '^ C>J Oi OS CO '^ lOQOiOCDOi 
C^WCO^ CN C<J ^ 'C^C>1^CO<M 


Oa^0000cD0i i rf •« 
CQ^COCN^CO '-H 'CO 


OO 




»0 CO 00 O CD 00 I-" t^ 1 O CT) '^ O »0 

COCOCOt^CDr~.iOai lO'^^CiOiO 
^ ^^ ^ 1 -H <M (M ^ ^ 


CCCO-^CO^CO 'I-- iM 

u:, ^ „ ^ ccj r^ ' c; lO 


t^ 


c 

c 
O 


^^5 


'^OiOOtCOOiOiOO'"* iC^Oi 


O OO CI •-"-' 00 CO it-^ 


CO 


OOCr-»OCO— 'WiCCOC^COOl lOO^ 
O) <M CO ■^ " CO CI C^ Ca *M <M 'COCO 


C^OiOi'^CO'— 'CO lOS 
d — CO CO CI Tf CO 'C^ 




oocoiocoocr^-— -rococo -c^c^ 


00 •-' ^ OO t^ O O) it- 


CR 
CI 


CI -r CO --C' y:: ic CO c7 o 00 CO ■ »c cd 


-j. ^ — — c; CO uo • -^ 


o 




OOW5'-»tCiOcDOcDcDOS(McD^H 


'"fOOOi'TjiOCO-rJ'^OcC 


en 
CI 


00(MiOCQOi-^*CiiDO»0'rf-(t^-C^ 
C4COCOIM — CO<M(MdC3CO(MCOCO 


t^TTOOCOcDCI'TfCDClTj- 
CI CJ CO CO CI 'Tt- CO CI -t cc 




h-OiClCO»QlQOOCOCOCq'fcD^-d 


OCOl^-^OOiO-^^OOf^ 


CI 


ClCJCOOlOiiOCId^yDcDCO-^J'lC 


ocn^c^coc^4co^co*f: 

- 1 1 


o 

c 
c 

O 


"■i 


CO 00 CO OO " *-• CO ^ 'Tf IC 00 iCDOO 


COCfilOCROOt-^COCOCO 


CO 


00 CO OO -^ CJ CO CD o; (M OO CO 1 CC (M 
Cq CO CO M CJ CO C3 CJ (M C3 -* 'COCO 


^^ OO o -rf r>- CI CD t* CI 

COCl-^COd-rrCOCliO 




-* oo o ooo c^ «:ioo ^ -^ CO ■ ^ o; 


iCnOI---:fV';ft— OOCl 


o 
Ci 


ClOOOCDt^'^J^^HCDCJCO^ -lOCO 

+ + + +- :- 


w500cO'^oco^-^- 

+ 11+4- ^ 


o 

c 
o 

O 




CTClO'^QO-rtCOOiOdOJ 'CDO 


Ol -^ CI OO CO CO CD ICO 


?5 


OilC05:0 — --fOOOCM'^CT; -h-CC 
C4COCOd(MCOCMCOCOCOCO 'COCO 


eocic^'+i^cjoc ICO 

CO CO -rr CO CO '^f CO 1 *c 




CO«0"iO(MascDt^CO»C 'OOO 


CO iO CD 00 O t^ CO "* 


O: 


O CO 1— •*<-*• ^ —CO OO OO ti— (M 

1 I++ 1 +1 :- 


— OC5C5000 'CO 

+ 1 1 I 1+ :- 


CO 

o 

o 
O 


'4. 


COiOOOOOCO»OC00501C)CO lOCO 


Od-^CIOiOcDOCO 


o 


O CO CTi r^ lO -^ QO " Csl ^ O 1 Ol CO 
COCOCOCMCICOMCOCCCO^ 'COCO 


iC^OiOO'^QOCir' 

COCOfCOCO-t-COCOiC 


¥■*■ 


»or-cooot^ocO'«*«»-i-*oo iioo 


co'^t^ci^H^^or^-^ 


CO 
OO 


'OCO^OlC^^'MCOOOr- iCDCl 

11+ 1 +1 ; 


— — OCOOOOCiO 

1 M 1 1 + +- 


00 

o 

o 
Q 


''" 


TfCJ^OlfMO^-^-CliOO '(M»f:! 


t--c^r^cooor-— ica 


CJ 

cr. 
CO 


Ot'-CiOOO'+'a: CICO— '— ' 'OiCl 
COCOCOCOCICOCJCOCOCO-^ iCOCO 


-^* CI a: '^ — '>^ CO t- 
CO CO CO CO CO "<*• CO 1 »o 


€ 


CD CD O '-"C^ t^ CO ^ CO CD iM 'CDilO 


TjH »r4 »C t^ CO OO O "^ 


T 


7-7T7^T"T7- ;«- 


TTT7 I'TT \° 


o 

s 

C 

o 




^ — „ — (M lOCO O OCOI-^ 'OOCO 


cDiOOrfCOCIiOOiO 


1 


CTth-0:O31C0C0CIC0t-HO lOOCO 
<M CO CO CO CI CO CO CO CO CO 'rf 'COCO 


COCO'^COCO-'fCOCOiC 


..^ 


CJ '«*• 00 OO CD ^ I^ -rf ^ l>- rP ' — OO 


00''fiC0005l>-lOCOCO 


\ 


^ — — — C-1C51CCO— '1— '1^ .■-*<.-. 

l+l 1 1 1 1 II ; 


(MOOMC4OOCI00 

1 MINI 


1^ 


CliOcO'Tt^iOCrS'rfiOOOOCOiOcOCO 
'— CJCOCnOiO— «COcDcDt--iCO000 

— — — — — c^c^c^i 


cDif3CI00 — t'OOOCi'rt 
— lOOOOOWcOI^-COCCOC 

— — ^ d CI c 


CO 

CD 


Class 


No... 


OS 


o 


- 



(1h 

£5 



S 

> 



6§ 



CLAY RESOURCES AND CERAMIC INDUSTRY 



319 



Al)sorption and linear shrinkage curves for clays of class 9. 



i2 
I 

I 



I 
I 



010 C8 Ob Of OZ I 3 5 7 9 II n /^ 









A 






No 


19 






, 






10 


20 

10 




















—' 






S 
























^ 






He 


25 




























s 






. 






_s_ 


^ 


-- 


— 


— 


-- 




^ 










jA 






No 


56 












20 
10 


10 


10 




































S 














.. 


.. 








^ 






No 


2A 
















A. 


^ 


-- 


s 

r" 




Ci 


— 


N 










^ 






No 


35 












rJ 




s 


-- 


— 


> 


.-- 


-- 


~ 


^ 







010 08 06 0^ OZ I 3 5 7 9 II 13 /T 

5 2ot 



10- 







/V£AT rREATnfN T IN C0/V^5: 



I 

I 



o 

10- 


10- 








T 


' 


— 


— 








No 99 








S 










^» 







-- 






















No 


II 


4- 


^ 




^ 


— 


^ 


— 


















s 












.. 


^ 




" * 




A 














No 


13 


5 


— " 






^ 


^ 


^ 


W 
















S±i 


ss 


.5. 




^^ 


•• " 


*v 


•= 










-7^ 


\ 


--1 


^_ 








No 


16 


& 






S 




^ 














~~ 








-^ 


_ 








No 


169 






A 


ir< 




J. 




^^ 


— 


— 


N 


^-— 


-- 


..^ 








_ 



HEAT TREATHENT IN CONES. 



tt: 

U, 

i 

-J 

I 

I 



OlOqSOi, 0^ OZ I 3 5 7 S II 15 IS" 



20 

10 



10 



30 

20 

10 
O 
£0 
10 




- 




A 


*^ 


*V, 


No 


17 


3 




















N, 


- 


^ 


s. 








-. 


— _ 


_S 


-- 


•** 


^ "* 


■' 






















No, 




5 




_s 


.* 
















<] 


■— 


^ 


< 


^ 








A 






No 


lb 


3A 
















^ 




— 


^ 


— 


- 






— 
































_S 


— 


— 


— 


'' 


-- 


-- 


— " 


— 




- 




_A_ 






No 


25 


3B 
















^^ 
























Jt* 


.S. 


.. 


.. 


^^ 


,^m 


— 


— 




— 





HEAT TREATnENT IN C0NE5. 



320 



DIVISIOX OF MINES AND MINING 



Absorption and linear shrinkage curves for clays of classes 10 and 11. 



610 08 0b (H 02 I 3 5 7 S II 13 IS" 



I 

a; 

I 

-J 



I 



20 
10 


20 
10 


20 
10 


20 
10 









,A 






No 


16 




















■^ 


X 


















5 




^ 


-- 


— 


^ 


"" " 


'■ 


>1 












A 






No 


55 




















>-. 


V. 


















5. 




^' 




— 


^ 




-- 


>i 




— 




"a" 






Nc 


82. 














































S 
















k 




— 




A, 




- 


No 


38 














s 


— 


V 












S 








i 




\ 


tzz. 






^^''M 


^/T? 


'^ 


)^A 


fn 


fN 


Til 


vo 


om 


:S. 





•^ 



010 08 Ob Of OZ I 3 5 7 9 II IJ isr 



«^ 20 



Q» 



5 



1 10 



0=^: 



tt: 
^ 10 

^ 20 



frS 


10 


V 




5^ 





>. 




^ 




v:; 


?n 


ti 




^ 




^ 


10 


t-*! 




•^ 




*^ 






1 




A 






No 


II 


1 








-n 








"^ 


— 




s 
















S_ 




.. 


_- 




>. 


e.^ 


< 


- 








a" 


^"" 


^^" 




^ 


^ 


No 

■ — , 


16 


7 




















\ 


^ 








s 








.. 


^^ 


.- 


,''\ 








A 


^ 




No 


17 












































S 






.. 


















A 






No 23 


8 
















^ 


•- 


■^ 


















_S_ 


— 


— 




- 


=*i; 


** 









AZVir TREf\Jt1£NT INC0NE5. 



010 08 0b 0'^ OZ I 3 5 7 9 II 15 L 



lO 

^ 




CO 


.so 


^ 




Ct 




^ 


<w 


u, 




>^0 




2^ 


^0 


■2: 




ft 


20 


(o 




(.o 




^ 


m 








n 


or 




<r 




^ 


20 






-J 




♦« 


10 




•« 




§" 





> 




VI 




C 


?0 


<4 




u- 




i^ 


10 


s 




t 




ih) 














n 




No 


26 


9 








■~~- 




<, 


























^ 


\ 
























N 


\ 
























> 














— — 


— 




-- 


^ 




No 


26 


4 






















A 




























■^ 














^ « 


»• 


_S_ 


-- 


-- 


— 






\, 


A 








No}l6 


6 














\ 










/ 










^ 


S_ 


^'' 


<c 


"V. 


^ 
> 


— — 


f 









/ViVfr TREfimfNT IN CONES. 



(LAY RESOURCES AND CEUAMIC INDUSTRY 321 

III. RED-BURNING CLAYS. 

A. Open- Burning, Do Not Attain Less Than 6% Apparent Porosity at Any 

Temperature Short of Actual Fusion. 

12. ]\I{'(liuiii 1() 1 1 lull strength. 

^'o. 8 (p. 163). Riverside County. Alberhill C. & C. Co. "Red Clay 
N'o. 2." This is used ]ii'iii(M]ially as a rcd-eolorinp- day in the nianu- 
facturc (if I'licc hi-ieiv and other higli-^'rade red-bnrnetl pi'oduets. It is 
siiiiilai' in its properties to No. 7 (class 13), but is not (juite as uniformly 
line-grained, has gi'eater sliiiidvage and strengtli, and vitrifies more 
tlioi-ongldy at eone 13. The eolors ai-e as follows: dry, 11"1); wet, 11"; 
cones 010 to 3, H'b; cone 5, !)"b ; cone 7, 7"b; cones 9 and 11, 5"; and 
eone 13, 5"'"b (flashed). Finger-nail liardne.ss is found at cone 08, 
and steel liardness at coiic !>. The total linear shrinkage, i)lastic basis, 
at eone 13, is 1.1.8^7 . Tlie softening i)oint is cone l!)-2(). The best 
firing range is from cone 08 to cone 11, and especially good results are 
obtained from cone 1 to cone 7. 

No. 18 (p. 1()3). Riversi(h' County. Alberhill C. & C. Co. "Clark 
Tuiiiiel ^Mottled." This is a i)lastic red-burning clay, used in sewer- 
pi l)e mixes to increase! the vitrification range of the mix. It contains 
15.6/^ of -|-2()()-mesh .sand, has excell^init 'plasticity, medium dry 
strength, and in the dried state is medium hard and has a medium 
grain. The colors are: drj^ ll"b; wet, 9"; cones 010 to 06, 9'b; cones 
04 to 02, n/; cones 1 to 7, 9'i; cones 9 to 11, 5". Finger-iuiil hardness 
is (levelo])ed at cone 010, and steel hardness at cone 3. The total linear 
shrinkage, plastic basis, is 17.8% at cone 11. The softening point is 
eone 19. The be.st firing range is from cone 1 to cone 11. 

No. 24 (]). 163,). Riverside County. Albei-hill C. & C. Co. "West 
Tunnel ^Mottled." This is a red-burning clay used in sagger mixes 
and face brick. It contains 13.8% of -|--00-mesh .sand and has smooth 
and .strong plasticit}', medium dry strength. In the dry condition it is 
medium-hard, fine-grained, close-textured, with a tendency to laminate. 
The colors are: dry, ll"d; wet, 9"; cones 010 to 04, 9'b; 'cones 02 to 3, 
7"b ; cone 5, 9" ; cone 7, 5"k ; cone 9, 5"i ; cones 11 and 13, 1'". Finger- 
nail liardne.ss develops below cone 010, and steel hardness at cone 7. 
The specimens appear to be well vitrified at cones 11 and 13, but the 
absorptions are greater than 10%, at these temperatures. Some of the 
test pieces are slightly cracked. The maximum total linear shrinkage, 
plastic basis, is 14.2% at cone 11. The softening point is cone 18-19. 
The best firing range is from cone 5 to cone 11. Slight bloating is 
noted at cone 13. 

No. 26 (p. 163). Riverside County. Alberhill C. & C. Co. "West 
Yellow Stripping." This is used for face brick and sewer-pipe. It 
contains 21.8% of -4-200-mesh sand and has a smooth and strong plas- 
ticity, exceptionally high diy strength, high drying shrinkage, and 
medium firing-slirinkage. It laminates easily, warps badly in drying, 
and in the dry state is hard, with a fine grain and close texture. The 
colors are: dry, 19"; wet, 19"i; cone 010, ll"b, cones 08 and 06, 9"; 
cone 04, 11" ; cones 02 to 3, 7" ; cones 5 and 7, 5" ; cone 9, 7" ; cone 11, 
5'"; cone 13, 5'"i. The fired colors are excellent for the darker shades 

-'1 — 54979 



822 DIVISION OF MINES AND MININO 

of face brick. Piiifrer-uail liardiiess is present in the dry condition, 
and steel hardness appears at cone 1. Absorptions below 10/^ appear 
at cone 02. Bloatinff lieojins at cone i). The total maximum linear 
shrinka<re, plastic basis, is ISSt'/i , at cone 7, and bloatinjr appears at 
liijrher temperatures. Tlie best firinpr ran<re is from cone 02 to cone 7. 
The clay is especially valuable for its hi^h dry and fired strength, and 
its wide vitrification range at commercial temperatures. 

No. 32 (\). 205) . San Diego County. Linda Vista. Vitrified Products 
Co. A yellow clay-shale of Tertiary age. It is used for structural 
ware. It has good plasticity, medium high dry strength, and good dry 
condition. Some lime is present, wliicli does no harm if tlie larger lime 
boulders are avoided in mining, and if the mix is well prepared in the 
plant. The colors are: dry, 17"d ; wet, 17"; cone 010. ll'b; cone 08, 
11' ; cones 06 to 02, 9' ; cones 1 and 3, 5"'k. Finger-nail hardness is 
present in the dry state, and steel hardness appears at cone 04. In the 
sample tested, the maximum total shrinkage, plastic basis, is 11.2%, at 
cone 1. The absorption at this point is 8.7%. and at higher tempera- 
tures bloating begins, accompanied by the development of yellow-green 
colors typical of the presence of lime. It is possible that the sample 
contains more lime than is usually present in the material delivered 
to the plant. The best firing range is from cone 010 to cone 1. 

No. 3.-) (p. 202). San Diego County. Cardiff. C41adding, ]\IcBean 
and Co. This is a red-burning face-brick clay with excellent plas- 
ticity, high dry strength, and safe drying properties. It contains 16.4% 
of -j-200-mesh sand. In the dry state it is hard, and has a medium 
grain and open texture. The colors are : drv, 17"f ; wet, 15"d ; cones 
010 and 08, ll"b; cones 06 and 04, ll'b; cone 01, 9'b; cone 1, 9'; cones 
3 to 7, 7"; cones 9 and 11, 5"i ; cone 13, 13"i. The fired colors are 
excellent intermediate shades for face brick. Finger-nail hardness 
appears below cone 010, and steel hardness at cone 1. Vitrification is 
well advanced, but not complete, at cone 13. The total linear shrink- 
age, plastic basis, at cone 13, is 14.6%. The softening point is cone 
17-18. The best firing range is from cone 1 to above cone 13. The 
long firing range and high dry strength of this clay are its specially 
desirable features. 

Vrt. i() (p. 203). San Diego County. Xear Carlsbad. Pacific Clay 
Products Co. "Kelly Ranch Yellow." This is a red-burning, i)lastic 
clay with a long vitrification range, from a bed underlying that from 
which sample Xo. 39 was taken. It is suitable for the manufacture of 
face brick, sewer-pipe, roofing tile, and similar products. The sample 
contains 4.8% of -|-200-mesh sand. It has a smooth, strong plasticity, 
high dry strength, and the dry .structure is hard, fine-grained, and 
dense. The colors are: dry, 17"'b; wet, 17"i; cones 010 to 04, 9'b; 
cone 02, 9'; cones 1 to 5. 9'i; cones 7 and 9. o". The fired colors cover 
a good range of brilliant reds for face brick and roofing tile. Finger- 
nail hardness is approached in the dry state, and steel hardness appears 
at cone 08. Porosity under 10 /r is found at cone 1. and bloating begins 
above cone 5. The total maximum linear shrinkage, plastic basis, is 
18.9% at cone 9. The softening point is cone 18-19. The best firing 
range is from cone 02 to cone 13. 

No. 6') (p. 141). Orange County. Brea. Brea Brick Co. This is a 



CLAY RESOURCES AND CERA^IIO INDUSTRY 323 

rctl-buniinji: surface cIjiv suitable \\)V the nianur.U'turc oi" coinnuiu brick. 
It effervesces sliprlitly in iiydrochloric acid. The jilasticity is good, 
with a tendency id become sticky Avilli exc(\ss watiu'. tlie diy strength is 
liU'diuin hitrli. and the dry condition is hard, (h'use, and granular. Tt 
contains 4').'2'/r of -|--'**'-J"t'^h sand. The colors are: drv, 17'"b; Avet, 
l.V'k; cones 010 and 08, il'b; cone 06, !»'; cone 04, g'iTcone 02, 9'k; 
cones .'{ and 5, 5'k; cone 7, 5"in. The fired colors are excellent for 
common brick. Finger-nail hardness is ol)tained below cone 010, and 
steel hardness develops at cone 3. Vitrification is comi)lete at cone 7, 
and bloating begins below cone !). The fired condition is souiul, open, 
and strong. The nuiximum total linear shi-inkage, plastic basis, is 
11.9 /( , at cone 7. The best firing range is from cone 010 to coti(> 7, 
and good structures are obtained from cone 3 to cone 7. 

No. 6.9 (]). 169). liiverside County. 10 m. south of Coi-ona. Emsco 
Clay Co. "Red Horse." This is a red-burning clay with smooth, 
strong plasticity. It is suitable as an ingredient of red earthenware, 
roofing tile, face brick, and sewer-pipe mixes. The sample contains 
I'-i.H'/r of -|-200-mesli sand. The dry strength is medium, and the dry 
condition is medium hard, fine-grained and close-textured. The colors 
are: dry, 9'b; wet, 9'i ; cones 010 to 04, 7'b ; cones 02 to 3, 9'; cone 5, 
7''; cone 7 to 11, 5''i. The fired colors cover an interesting range of 
deep reds. Finger-nail hardness is developed below cone 010, and steel 
hardness at cone 04. Vitrification is practically complete at cone 7, 
but the apparent porosity is still above 8 per cent. All test pieces 
above cone 08 are slightly cracked. The fired condition is strong, 
tough and fine-grained. The total linear shrinkage, plastic basis, at 
cone 7, is 14.4%. The softening i)oint is cone 18-19. The best firing- 
range is from cone 04 to cone 7. [The shrinkage and apparent porosity 
data at cones 11 and 13 were lost. See absorption curve for general 
trend.] 

Xo. 73 (]). 169). Riverside County. Em.sco Clay Co. "Bone." 
Although this is locally" classed as a bone clay on account of its pisolitic 
structure in the raw state, it is lateritic, and contains so much iron as 
to give a low^ fusion point. It contains 46.8% of +200-mesh material. 
The iilasticity is spongy, ])ut fairly strong, the dry strength is medium, 
and the dry condition is granular, and o])en-textured. The colors are : 
dry, 9'd; wet, ll'i ; cones 010 to 04, ll'f ; cones 02 to 5, 7'^b ; cone 7 to 
11, 9"'b ; cone 13, 5''''k. The fired colors are suitable for red face brick 
and roofing tile. Finger-nail hardness is develoi)ed below cone 010, and 
steel hardness at cone 1. All fired test pieces are sound, granular, and 
strong. Vitrification is complete at (approx.) cone 7, bej^ond which 
temperature, bloating gradually develops. The maximum total linear 
shrinkage, plastic basis, is 9.2^t, at cone 7. Absori)tions below 10% 
are obtained at cone 02 or higher. The softening point is cone 15. 
The best firing range is from cone 02 to cone 7. The clay can be used 
as a coloring agent, and to prolong the vitrification range of red-burned 
structural ware. 

Xo. 100 (p. 171). Riverside County. Alberhill. G., McB. & Co. 
"Yellow Striii])ing." This is an impure, sandy clay that is used in 
face-brick and sewer-pipe mixtures. It effervesces slightly in hydro- 
chloric acid. The plasticity is good, the dry strength is exceptionally 



324 DIVISION OF MINES AND MINING 

high, and in the dried condition the clay has finger-nail hardness, and 
is dense and fine-grained. It contains 20.8% of 4-200-inesh sand. 
The colors are: dry, 15"d ; wet, 17''; cones 010 to 02, 9'b; cone 1, 9'i; 
cones 3 to 11, 5'i. Steel hardness is developed at cone 06. Absorptions 
below 10% are obtained from cone 02 to cone 9, inclusive. All fired 
test pieces are sound, and have a stony structure. Vitrification is 
complete at cone 5, and bloating begins above cone 9. The maximum 
total linear shrinkage, plastic basis, is 17.3%, at cone 5. The softening 
])oint is cone 14-15. 

No. ion (p. 171). Riverside County. Alberhill. G., IMcB. & Co. 
"Sloan lied." This is a red-burning clay with good i)lasticity, medium 
dry strength, and in the dried condition it is soft, medium-grained, and 
open-textured. It contains 17.0% of -|-200-mesh sand. It is used for 
face brick, roofing tile, and .similar products. The colors are : dry, 
ll'd; wet, 9'k; cones 010 to 5, 9'b; cone 7, 7"b; cones 9 to 13, 5"i. 
Finger-nail hardness is developed at cone 06, and steel hardness at 
cone 1. The fired structures are all sound and stony, with a slightly 
roughened surface texture. Absorptions below 10% are obtained at 
cone 7 or above. The total linear shrinkage, plastic basis, at cone 13, 
is 15.0%. The softening point is cone 18-19. 

No. 112 (p. 178). Riverside County. Alberhill. P. C. P. Co. 
' ' Hoist Pit Blue. ' ' This is a plastic, pink-burning clay that is used in 
sewer-pipe mixes. The plasticity is excellent, the dry strength is 
medium, and in the dried condition the clay is soft, medium-grained, 
and open-textured. It contains 25.0% of -|-200-mesh sand. The colors 
are : dry, 17'"b ; wet, 19''k ; cones 010 to 02, 7'd ; cones 1 to 7, 7''d ; 
cone 9, 9'''d ; cones 11 and 13, 13'"i. Finger-nail hardness appears 
below cone 010, and steel hardness at cone 1. Absorptions below 10% 
are obtained at cone 7. The fired structure is sound and heterogeneous, 
and the fired surface texture is smooth. The total linear shrinkage, 
plastic basis, at cone 13, is 16.1%. The softening point is cone 19. 

No. 113 (p. 176). Riverside County. Alberhill. P. C. P. Co. 
"Hoist Pit Red." This is a red-burning sandy clay of use in sewer- 
pipe mixes, roofing tile, red earthenware, etc. It contains 18.6% of 
-|-200-mesh sand. The plasticity is excellent, the dry strength is 
medium high, and in the dried condition the clay is hard, brittle, fine- 
grained and close-textured. The colors are : dry, 9'b ; wet, 7'i ; cones 
010 to 7, 9'; cones 9 to 13, 9"'. Finger-nail hardness (nearly) is 
present in the dried state, and steel hardness appears at cone 3. The 
fired condition is sound and fine-grained, and the fired surface texture 
is slightly rough. The total linear shrinkage, plastic basis, at cone 13, 
is 11.3%. The softening point is cone 23-26. 

No. 117 (p. 131). Santa Cruz County. Castroville. Joe Area. 
This is an excessively plastic surface clay, that can almost be classed 
as an adobe. It is used for making hand-made roofing tile on a small 
scale. It has an exceptionally high dry strength, but must be dried 
carefully to prevent warping and ei-acking. In the dried condition it 
is dense, fine grained, and has finger-nail hardness. The colors are : 
dry, 17"'b ; wet, 17"'i ; cones 010 to 06, 9'b ; cone 04, 9' ; cone 02, 9"i. 
Steel hardness develops at cone 02. Bloating is well advanced at cone 1. 
All test pieces cracked on firing. The maximum total linear shrinkage, 



CLAY RESOURCES AND CERAMIC INDUSTRY 325 

plastic basis, is 18.0%, at cone 02. Most of the shrinkage takes place 
iluring drying. The best firing range is from cone 010 to cone 02. 
The short vitrification range and the poor drying qualities of this clay 
preclude its general use for structural-clay products. 

No. 119 (y). 1^). Contra Costa County. Point Richmond. Richmond 
Pressed Brick Co. This is one of tlie tyi)ical red-burning Tertiary clays 
of the San Francisco Bay region that are widely used for the manufac- 
ture of common brick and buikling tile. As ground, the sample con- 
tains 43.2% of +200-mesh sand. The phisticity is good, the dry 
strength is medium, and the dried condition is hard, medium-grained, 
and open-textured. The colors are : dry, 17'^^' ; wet, 17""i ; cone 010, 
13"b; cone 08, ll^'b; cones 06 and 04, 9''; cone 01, 7"i; cone 1, 5'k. 
Steel hardness is developed at cone 04-f-. Vitrification is complete at 
cone 1, and bloating begins at sliglitly higher temperatures. The fired 
.structure is sound and fine-granular, and slightly roughened surface 
textures are obtained. The maximum total linear shrinkage, plastic 
basis, is 12.1%, at cone 1. 

No. 155 (p. 151). Placer County. Lincoln. Gladding, McBean & Co. 
"Pit Sand." This is a red-burning sand-clay mixture that is used in 
tlie manufacture of roofing tile, sewer pipe, and other red-body ware. 
The residue on 200-mesh is 31.8%. The ])lasticity is fair, the dry 
strength is medium high, and in the dried condition it is hard, medium- 
grained, and open-textured. The colors are: dry, 17''"d ; wet, 17""; 
cones 010 to 06, 13"; cones 04 and 02, 1"; cones'l to 5, ll"i; cone 7, 
5"m. Finger-nail hardness is present in the dried condition, and steel 
liardness is developed at cone 1. The fired structure is sound, except for 
light hair-cracks on the surface. The fired surface texture is rougli. 
Bloating begins at cone 7, before the body is vitrified to a low absorj)- 
tion. The maximum total linear shrinkage, plastic basis, is 15.0% , at 
cone 5. 

iVo. 77^ (p. 66). Butte County. Oroville. Quincy i-oad. This sample 
is representative of a residual deposit of decomposed granite. The plas- 
ticity is fair, the dry strength is medium high, and in the dried condition 
it is medium hard, coarse-grained, and open-textured. The colors are : 
dry, 15"d; wet, 15"; cone 010, 15"; cone 08, 13"; cones 06 and 04, 11'; 
cone 02, 9' ; cone 1, 7'i. These are good colors for common brick. 
Steel hardness is not developed up to cone 1. the upper temperature 
limit studied. The fired structure is .sound and granular, and the sur- 
face texture is moderately rough. The total linear shrinkage, plastic 
basis, is 8.2%, at cone 1. The material is suited for the manufacture of 
common brick. 

.Vo. i78 (p. 66). Butte County. Palermo. Lund Brick Yard. This 
is a clay-gravel mixture from a Tertiary river channel and is being used 
for the manufacture of common brick. Three separate samples were 
taken. No. 178-1, 2, and 3, each representing different phases of the 
material. Only one of these. No. 178-2, was tested completely. The 
others were fired to but three different temperatures each. The differ- 
ences between the three varieties are the result of differing proportions 
of sand, silt, and gravel. No. 178-1 contains 51.6% of +200-mesh sand, 
No. 178-2 contains 23.6%, and No. 178-3 contains 15.2%. This descrip- 
tion covers No. 178-2, and the reader is referred to the tabulated data 



326 DIVISION OF MINES AND MINING 

for the results on the other samples. The plasticity is strong, but with a 
tendency to stickiness when excess water is used. Tlie dry strength is 
higli, and in the dried condition it has finyer-nail hardness, is medium- 
o-rained, and open-textured. The tendency to laminate is pronounced. 
The colors are : dry, ll'b ; wet, ll'i ; cones 010 to 3, 9'i ; cone 6, 5'k. 
Steel hardness is developed at cone 02, and less than 10/r absorption at 
cone 6. The fired structure is strong and stony,* with a slight tendency 
to crack. The surface texture is moderately rough. The total linear 
sliriid<age, i)lastic basis, is 15.8%, at cone 6. The best firing range is 
from cone 02 to cone 6, for hard-burned ware, and from cones 06 to 02 
for soft-burned ware. The material makes a strong brick with good 
colors, but the irregularity of the de))osit is i\u uncertain factor that 
makes the close control of shrinkage difficult. 

No. 180 (p. 77). Del Norte County. Crescent City. Elk Valley. 
Tliis is a common-brick clay. The ])lasticity is good, the dry strengtli 
is medium, and in the dried condition it is hard, fine-grained, and close- 
textured. It contains 19.2^/c of +200-mesh sand. The colors are: dry, 
17''b ; wet, IT'^i ; cones 010 to 06, 9' ; cones 04 to 3, 9'i ; cone 6, 5'k. 
Steel hardness is developed at cone 1, and less than 10*^/ absorjition at 
cone 3. All test pieces are sound. The total linear shrinkage, plastic 
basis, is 17.5%. The best firing range is from cone 010 to cone 3. The 
clay is entirely suitable for the manufacture of red brick either by the 
soft-mud or stiff-mud process. 

No. 183 (p. 81). Humboldt County. Eureka. Thompson Brick Co. 
This is a common-brick clay with good i^lasticity, high dry strength, 
and in the dried condition it has finger-nail hardness, is fine-grained and 
close-textured. It contains 16.8% of -|-200-mesh sand. The colors are: 
dry, 17"d; wet, 17"k; cones 010 to 06, 11'; cone 04, 9'; cone 02, 7'i ; 
cone 1, 7'm; cones 3 and 5, 7"m. Steel hardness is developed at cone 
010, and less than 10% absorptioji at cone 02. The fired structure is 
generally sound, but with a tendency to crack. Bloating begins above 
cone 3. The maximum total linear shrinkage, plastic basis, is 16.6%., at 
cone 3. The clay is mixed at the ]ilant with a sandier variety to insure 
safer drying and firing. 

No. 183 {]}. SI). Humboldt County. Eureka. Second Slough. This 
is a common clay that has not been used. It has sticky plasticity, high 
dry strength, and in the dried condition it is hard, medium-grained, and 
close-texturod. The colors are: dry, 17"d; wet, 17"k ; cones 010 to 08, 
9'd ; cones 06 and 04, 9'b ; cone 02, 7" ; cone 1, 5"k ; cones 3 and 5, 5"m. 
Steel hardness and less than 10% absorption are developed at cone 02. 
The fired structure is sound, uji to cone 1, beyond which bloating begins. 
The maximum total linear shrinkage, i)lastic basis, is 18.9'X, at cone 1. 
The clay Avould be satisfactory for common-brick manufacture, if 
mixed with less plastic material. 

No. 199 (p. 74). Contra Costa County. Port Costa. Port Costa 
Brick Co. This is a plastic, red-burning Tertiary shale that is used for 
the manufacture of common brick and hollow tile. There is strong 
effervescence in hydrochloric acid. The i)lasticity is good, with a 
tendency to stickiness, and dry strength is medium, and in the dried 
condition it is medium-hard, medium-grained, and close-textured. The 
sample, as ground, contains 40.2% of -j-200-mesh sand. The colors are: 



CLAY RESOURCES AND CERAMIC INDUSTRY 327 

dry, 21""f; wet, 21""; cones 010 to 04, ll'b; com' 02, })' ; cone 1, 7"; 
cone 8, 7"k. Steel hartlness is developed at cone 04. and less than 10% 
absorption at cone 02. The fired structure is sound, up to cone 1, above 
which bloatin<r begins. The .surface texture is .sliprhtly rough. The total 
linear shrinkage. i)lastic basis, is 14.8V,, at eoiu^ 1. The best firing 
range is from cone 04 to cone 1. 

.Yo. 505 (p. 282). Tulare County. Porterville. Black slate. This is 
a black slate that develops good plasticity, medium dry strength, and 
fires to a red color. In the dried condition it has finger-nail hardness, 
is coai-se-grained, and open-textured. ft should be finely ground to 
avoid excessive lamination. The colors are: dry, 15"'"; wet, nearly 
black ; cones 010 and 08, 17"b ; cone 06, 18"b ; cone 04, 11" ; cone 02, 7". 
Steel hardness is developed at cone 04. The fired structure is sound and 
strong and the surface texture is I'ough. The total lineai- shrinkage, 
plastic basis, is 1.9'/t . at cone 8. This should be a good clay for com- 
mon brick and hollow tile. 

No. 211 (p. 131). Monterey County. Near Monterey on Salinas road. 
Monterey Mission Tile Co. This is an adobe clay that is used for the 
manufacture of hand-made roofing and step tile. The plasticity is 
strong and sticky, the dry strength is high, and in the dried condition 
it has finger-nail hardness, is fine-grained, and close-textured. Serious 
warping and cracking results in drving when the clay is used alone. 
The colors are: dry, 15""'; wet, 15""'k ; cones 010 to 06, 15" b; cone 
04. 11". Steel hardness and less than 10% absorption are present at 
cone 010. All test pieces cracked in firing, and serious bloating takes 
place at cone 04. The maximum total linear shrinkage, plastic basis, 
is 15.4%, at cone 06. This clay can not be used alone, but when grogged 
with crushed tile made from the same clay, very attractive hand-made 
tile can be made. 

No. 216 and 217 (]). 218). San Luis Obispo County. State highway 
2 m. south of Santa Margarita. These two samples are representative 
of a large deposit of red-burning shale. The shale develops good 
plasticity without the necessity of tine grinding. The dry strength is 
medium, and in the dried condition it is hard and close-textured. The 
colors are: dry, 17"i to 15"; wet, 15"k; cones 010 and 08, 11'; cones 06 
and 04, 9'i ; cone 02, 7'k; and cone 1, 7'm. Steel hardness and less than 
10^,' absorption are developed at cone 02. The fired structure is strong, 
but the test pieces that were fired at or above cone 02 are slightly 
checked. The total linear shrinkage, plastic basis, at cone 1, is 12.4% 
for No. 216, and 13.3%o for No. 217. The best firing range is from 
cone 04 to cone 1. The material seems entirely suitable for the manu- 
facture of hard or soft-fired heavy clay products, and is a possible 
material for paving brick. 

No. 251 {p. 52). Amador County. lone. Core drill hole No. 57-1, 
Arroyo Seco Grant. This is a red-burning clay with smooth and 
strong plasticity, and medium dry strength. In the dried condition it 
is medium hard, fine-grained, and close-textured. It effervesces slightly 
in hydrochloric acid. Some fine sand is present. The colors are: dry, 
15'd'; Avet, 15'b; cones 1 and 5, 9"b; cones 9 and 13, ll"i. Steel hard- 
ness and less than 10% absorption are developed below cone 1. Blister- 
ing is noted at cone 13, otherwise the fired structure is sound and 



328 DIVISION OF MINES AND MINING 

stony. TJie surface texture is smooth. Tlic maximum total linear 
shrinkage, plastic basis, is 18.8%, at cone 9. The softening point is 
cone 23. This clay is suitable for face brick. 

No. 261 {p. 159). Placer County. East of Lincoln. Valley View 
Mine. This is an iron-stained kaolin, witli fair plasticity and medium 
dry strength. In the dried condition it is hard, fine-grained, open- 
textured and heterogeneous. The colors are: dry, ll"d; wet, 15"b; 
cones 010 to 1, T'h; cone 3, T'd; cones 5 and 7, 13"; cones 9 and 13, 
15". Steel hardness is not developed at cone 3. The fired structure is 
sound, except for a few superficial hair cracks. The surface texture 
is moderately rough. The total lijiear slirinkage, plastic basis, is 17.7% 
at cone 13. The softening point is cone 28, yet it is distinctly a red- 
burning clay. The material might be used in face brick and terra 
cotta. 

13. Low Strength. 



o ■ 



No. 7 (p. 163). Riverside County. Alberhill C. & C. Co. "Pink 
Mottled." This is one of the important face-brick, roof-tile, and floor- 
tile clays from the Alberhill district. It is a fine-grained, pink-yellow 
mottled clay of medium hardness, develops a .smooth and strong 
plasticity, and has medium low dry strength. It contains 14.2% of 
+200-mesh sand. The colors are as follows: dry, ll"d; wet, 11"; 
cones 010 to 3, 9'b; cone 5, 7'd; cone 7. 7'b; cones 9 and 11, 7"; cone 
13, 7"i. These are good pinks and light reds for face brick, floor tile, 
etc. At cone 13, fine black specks appear, giving a not unpleasing 
mottled effect, which could be reproduced at lower temperatures by 
flashing. The fired surfaces have a smooth texture, capable of taking 
a polish. Finger-nail hardness is not developed until cone 06 is 
reached. The hardness at cone 13 is slightly less than steel, although 
vitrification is not complete at that temperature. The total linear 
shrinkage, plastic basis, is 10.5% at cone 13. The softening point is 
cone 17. The best firing range is from cone 06 to cone 11. 

No. 73 (y). 169) . Riverside County. Emsco Clav Co. "Red." This 
is similar to No. 8 (class 12) "Red Clay No. 2" from the Alberhill Coal 
and Clay Co. pits, but has lower drying and firing shrinkage, and 
lower strength. It is used mainly as a coloring clay in face brick, and 
other high-grade red-burning products. The residue on 200-mesh is 
12.6%. It has a smooth and moderately .strong plasticity, medium low 
dry strength, and a soft, fine-grained, close-textured dry condition. 
The colors are: dry, 7'; Avet, 7'i; cones 010 to 13, 9', with a slight 
darkening toward the higher cone numbers. Finger-nail hardness is 
developed below cone 010 and steel hardness at cone 3. The fired 
structure is tough and stony. Tlie total linear firing shrinkage, plastic 
basis, is 12.5%, at cone 13. The softening point is cone 20. The best 
firing range is from cone 02 to cone 13. Vitrification is practically 
complete at cone 11. 

No. 122 (p. 53). Amador County. lone. Arroyo Seco Grant, Jones 
Butte. Leased by Stockton Fire Brick Co. Laterite. This is a true 
laterite for which no ceramic uses have yet been found, but which 
occurs in sufficient abundance to be of possible interest. The sample 
contains a large proportion of non-plastic grains, and the plasticity 



CLAY RESOURCES AND CERAMIC INDUSTRY 329 

is weak and sliort. Tlie dry .sti-o]i<>:lli is nuHliiuu low, and the dried 
condition is modiuiii liard, incdium frrained, and open-textured. The 
colors are: dry, 5"; wet, 'Vi; cones OK) to :{, 5"; cones 5 and 7, 9"'; 
cone 9, 9"i ; eone 11, ll"k. Steel liardness appears at cone 1. Less 
than 10% absori)tion is i)resent at cone f}. The fired structure is 
^n-anular and hair-craeked. The total linear slirinkajje, plastic basis, 
at cone 11, is 17.5%. The softening point is cone 17-18. 

No. i:ri (]). 62). Amador roniily. lone. "Newman Red Mottled." 
This is a red-bnrniiifif clay witli «?ood ]>]asticity, low dry strength, and 
in the dried condition it is very soft, fine-gi-ained, and close-textured. 
It contains 'A:2% of -f'200-mesh sand. The colors are: dry, 9"b; wet, 
!)"; cones 010 to 02. 9')); cones 1 to 7, 9'; cones 9 to 13, 7'. Steel 
hardness appears at cone 1, and less than 10%j absorption at cone 11. 
The fired structure is stony, and at cones 11 and 13 several tension 
cracks appeared during firing. The total linear shrinkage, plastic 
basis, at eone 13, is 20.0%. The softening i)oint is eone 23-26. The 
best firing range is from eone 1 to cone 9. The clay can be used as a 
coloring clay for face brick, roofing tile, and similar ware. 

Xo. 171 (p. 136). Xeva(hi Connty. Xortli F.loomfield road. This is a 
i-ed-burning clay tliat could be used for common-brick manufacture. 
The plasticity is fair, the dry strength is medium low, and in the dried 
condition it is hard, fine-grained, and close textured. A tendency to 
develop drvinu- cracks was noted. Tlie colors are: dry, 17'f; wet, 
21"'; cones 010 to 06, ir)"b; cone 04, 15"d; cone 02, 11'; cone 1, 9'. 
The fired colors are suitable for common brick, roofing tile, etc. Steel 
hardness appears at eone 02, and less than 10% absorption at cone 1. 
The fired structui'e is stony, and is sound except for a few small cracks, 
which may have been formed during drying. The surface texture is 
snu)oth. The total linear shrinkage, plastic basis, is 16.1%, at eone 1. 
Xon-plastics should be added. 

No. 1.98 (p. 125). Marin County. San Rafael. ' McNear Brick Co. 
Til is is a red-burning, sandy, clay-sliale that develops sufficient plas- 
ticity for brick and liollow-tile making. The dry strengtli is medium- 
low, and in tiie dried condition it is medium-hard, coarse-grained, and 
open-textured. Tlie sample as ground contains 55.8% of +2^^^-"i^^'' 
material. The colors are: dry, 15"b ; wet, 15"i ; cones 010 and 08, 7'b ; 
cones 06 and 04, 9'b; cones 02 to 6, 9"b. Steel hardness is developed 
at cone 1. The fired structure is coarse-granular and open, and hair- 
cracks are prominent, especially when fired above coiu' 1. The total 
linear shi'inkage, plastic basis, is 11.8%), at cone 6. The best firing 
range is from cone 04 to cone 6. The sample contains more non- 
plastic nuitter than the normal run-of-pit material. 

No. 218 {p. IHl). Riverside County. 8 m. south of Corona. This is 
a pink-mottled clay with excellent plasticity and medium-low dry 
strength. It is similar to No. 72 (Emsco Red). In the dried condition 
it is medium-hard, brittle, fine-grained and close-textured. The colors 
are : dry, ll'b ; wet, 9'i ; cones 010 to 3, 11' ; cone 5, 7'b. Steel hardness 
is developed at cone 3. The fired structure is sound and stony and the 
surface texture is smooth. The total linear shrinkage, plastic basis, is 
19.5%, at cone 11. The softening point is cone 23. The clay is suitable 
for the manufaeture of face brick, roofing tile, and similar products. 



330 



DIVISION OF MINES AND MINING 



No. 256 (p. 52). Amador County. Tone. Core drill hole No. 60, 
Arroyo Seco Grant. This is a red-burning clay with good, but sticky, 
plasticity and medium-low dry strength. In the dried condition it is 
medium-hard, fine-grained, and open-textured. The colors are: dry, 
n"d ; Avet, 11" ; cone 1, 9" ; cone 5, 7"i ; cone 9, 9"' ; cone 13, 9'"i. Steel 
hardness is develo])ed at cone 5, and less tlian '[{Y/< absor])tion at cone 
13. Tlie fired structure is weak and hair-cracked. The total linear 
shrinkage, plastic basis, at cone 13, is 20.3 /< . The softening point is 
cone 19-20. This is not a good clay, but could be used as part of a 
face-brick mixture. 



TABLE No. 24. 

III. Red-Burning Clays. 

A. Opeii-buniins, tlo not attain less than 6% apoarent porosity at any temperature 

short of actual fusion. 

12. Medium to high strength. 



flay 














Soften- 
ing pt. 


No. % 


S.W. 


% P.W. 


% W.P. 


D.T.S. 


% D.V.S. 


</o D.L.S. 


in cones 


8 


11.7 


17.6 


29.3 


221 


21.1 


6.3 


19-20 


IS 


20.7 


21.6 


42.3 


305 


34.7 


10.4 


19 


24 


13.2 


19.7 


32.9 


252 


23.1 


7.0 




26 


28.7 


11.6 


40.3 


1569 


56. S 


16.1 




32 


16.0 


20.1 


36.1 


794 


27.6 


8.4 




35 


19.1 


12.8 


31.9 


1094 


37.3 


11.1 


17-18 


40 


22.7 


12.8 


35.5 


1412 


44.3 


13.0 


18-19 


65 


11.2 


12.9 


24.2 


569 


22.1 


6.9 




6U 


12.1 


15.4 


27.5 


265 


23.4 


7.3 


18-19 


73 


8.5 


13.5 


22.0 


334 


16.8 


5.2 


15 


100 


36.6 


12.8 


49.4 


1821 


71.4 


11.9 


14-15 


105 


11.4 


17.4 


28.8 


235 


21.0 


6.4 


18-19 


112 


11.9 


19.7 


31.6 


291 


20.8 


6.5 


19 


113 


13.4 


13.5 


26.9 


509 


26.2 


8.0 


23-25 


117 


30.4 


10.5 


40.9 


H-990 


63.0 


17.8 




119 


9.5 


13.5 


23.0 


374 


18.5 


5.8 




155 


23.3 


16.6 


39.9 


580 


42.3 


12.2 




176 


9.9 


19.2 


29.1 


615 


16.7 


5.3 




178-1 


22.6 


14.1 


36.7 


905 


44.1 


12.9 




17 8-2 


18.0 


12.8 


30.8 


1224 


35.8 


10.7 




17 8-3 


10.3 


14.7 


25.0 


498 


19.5 


6.1 




180 


18.6 


18.8 


37.4 


300 


32.5 


9.9 




182 


22.1 


10.0 


32.1 


1181 


44.7 


13.2 




183 


24.3 


14.4 


38.7 


-H983 


46.4 


13.5 




1!»9 


12.0 


14.3 


26.3 


352 


23.3 


7.3 




206 


5.1 


15.3 


20.4 


340 


9.6 


3.1 




214 


28.5 


12.1 


40.6 


-HlOOO 


54.4 


15.5 




216 


8.0 


15.8 


23.8 


305 


15.3 


4.9 




217 


10.5 


15.5 


25.9 


306 


19.9 


6.3 




•221 


21.2 


14.7 


35.9 


453 


39.0 


11.6 


26 


251 


17.6 


17.9 


35.5 


381 


31.4 


9.5 


23 


261 


17.1 


25.6 


42.7 
13. Low 


289 
strength. 


26.8 


8.2 


28 
Soften- 


CMay 














ing pt. 


No. % 


S.W. 


% P.W. 


% W.P. 


D.T.S. 


% D.V.S. 


% D.L.S. 


in cones 


7 


0.9 


18.0 


27.9 


149 


17.6 


5.3 


17 


72 


7.3 


16.4 


23.7 


133 


13.6 


4.4 


20 


122 


7.9 


22 2 


30.1 


110 


13.9 


4.5 


17-18 


131 


17.4 


22.8 


40.2 


9 4 


2 8.4 


8.6 


23-26 


171 


13.5 


24.6 


3 8.1 


-(-164 


20.9 


6.5 




198 


6.7 


18.9 


25.6 


166 


10.0 


3.2 




218 


12.9 


15.3 


28.2 


186 


24.3 


7.5 


23 


256 


16.8 
= Per 


23.5 
cent shrin] 


40.3 
kage water. 


156 


27.7 


8.4 


19-20 


% S.W. 




%P.W. 

% W.P. 


= Per 


cent pore 


water. 










= Per 


cent water 


• of plasticit; 


V. 








D.T.S. 


= Dry 


transverse 


strength, pounds per 


square inch, 


without sand 




% D.V.S. = Dry 


ing shrinkage, per cent 


dry volu 


me. 






<%,D.L.S. = Calculated linear drying shi 


finkage, per cent dry 


length. 





* Impure flint clay from Goat Ranch, Gladding, McBean & Co., Orange County, 
Description of ceramic properties omitted. See p. 141 for description of deposit. 



CLAY RESOURCES AND CERAMIC INDUSTRY 



331 





c- 


..£: 




c 






r. 










>t 




ri! 








o 






c 


,-, 




c 


a 


l-l 








3 




m 


fO 














tm 








« 5f 



00 

< 






O 







-•i 


1 1 1 1 1 1 I 




























<; 


: ; : : i i i 


























o 

5 


^i 


— ■ .— CO ■ O cs 
-^ -d CM ' .— 




ic ' 00 r^ CO 

00 ' ttJCsCl 












11.7 
12.0 
28.2 

24.4 
9.6 

"i6'2' 






eo 


CI 




.•» 






10.1 
26-2" 

m 6 

12 2 












1 1 CO CO »fl »C 00 ' o 

1 '-^ o Ci o eo «■»»* 

• i^Cl<M (M 'CO 











s 


"^ 


0© CO c: 00 ' ^ C^_ 

^^■.** OS 35 «C0»O 




^- 05 CO <M CO 

OC^OO OCO 












. t . - :o cr. h* ca »c 

I '. I lo 0:00^00 
. . 1 t eo c<j ^ u^i ^ 




C« " 

eo ' 




>- 


CO CO C-1 1 N lO 

c^iocioo "*r^ 

01 M W ' " 




(M sO Ol '^ »0 

^O*O00t-* 












, , . .CO C *C 00 

I 1 1 !oo — :coo 

1 1 < ■ <M — CI CO (M 




cs ■ 

-r ■ 

CO ' 




o 

c; 
c 
o 

O 


^*:: 


-r c^ -^o »o ■C'j -.*< 

C^ Oi ^CO 'COO 

CI (M ro -^ ' « 




r^io r^ too 
c» c; CI -* -^ 












■ .000 -J* CO :£; ^ 

I !ooh-— — iccjco 
' 1^ CO CO oaca c^ 




CI — 
C4 CO 




^? 


?© « eooo ' O '— 

^^COOO 'cf "(fCO 




40 CO Cl ^ 03 

CM OS -t" ifS O 












, 1 00 cT- r^ ^ ■-*• -rt- »o 




000 

c 

CO CI 




o 

o 

O 


.,5 


O^^Ci io — =C00C0-^C0Ort< 

iTSCSO-^ lOOOOt^OOtNCiOCt^^ 
(MOICO— ;^ -^ — — <N 










. . . . :© i^ooca 00 

I I I ! cj ^ -^ 01 00 

1 1 i 'CO CO «M C< CJ 




IC 
CI 




> 


-*C0-^»O ! t^ COCC'^OO t-*co»o 
c: (M »C '17 ■ ■ ^ ^ ^' ^^ S ~ I*^ °^ 

^ CI — — — C) — -7 1 — CI — 'M 










\ 1 ! I tc •-•ocsoo 

- . i 1 :o c<J eo 
, , , 1 c^a ^ ^ CO ci 








c 
o 
O 


^'" 


27.2 
32.3 
33.0 
15.5 
2() 

19 S 
12 2 

20 (i 

14 

15 3 
. 

22 () 
26.5 
28.0 




oo 

IM 




m ' CI i« C^ • ' 

cr^ ' CO o t-^ ' ' 

. — — CM 1 ■ 


t idOOC^ iCOOOO^C 

■ .COCO»C CO r^ CJ C:; 
< -d <— CO coc^ c^ 


^ CI oo 
r* 00 0: 

CI CI CO 




q5 eo'*onoO'*»«(MC<i!0«^»rtcvi'£J-^ 




CO 

CO 




19.0 

25"4" 

2.5 

-10.1 


. 1 (£5 CO -^f t* ^CO Oi 
. .--<M(M ^CO — 


•^ 00 
c^ ^ *^ 




o 
O 




27.7 
32 
34 5 

17 2 

18 8 
22 
13 4 
22-6 
20.0 
16 6 
110 
22.7 
28.6 
28.7 




o 




OO OO t>- OC O =0 .— 

■ eo Ci o: o t- oo :c 


. 1 1 1-^ »cooc^ •- 
. 1 1 1 ifio cocjcieo 


.^00 • 

'cioo • 
'CO ' 




> 


-i*'-*0300oO'*oo^cooo;--^*— CI 




P» 




■ »d^ oo O CJ CO :D 

, 1-^ O — tC o: IM Tj< 
_|_!M ^ — r^ — 


1 1 ! '0 0: COOOOO 

■•** »c eo t^ 

, . . . . (M ^ eo ■^ 


'OO OS ' 
■ OS OS ' 




5 
O 




20.2 
35 5 
34.8 
18.3 
16.3 
17.0 
15.2 
23 3 
22 I 
19.5 
14 6 
2t.l 
31.1 
28.0 

'7"0 
25 6 
HI) i\ 


O oo ' .»!- c; :C ic M 
' ic -f ' W2CC b- .<r <=> 

S (M CI ' Cfl -^ Cfl 


■ lO-'fooco-^ cr. :r-0!;0'rf — — 

• 500000:00 -J< 00 MOOCO ^ CO 

, ^<M.^eo eo eo CO CO -- CO CO ■* 




,o-J3 


<N -3- in lO =-. ^ OS t- t~ — CM t- CJ to . -.O O 35 OO •* | » OS O tO "3 

■js in ^. r-i o S-. 'ir ^ c> — 1~ -v" --o ■^^oa^t^-^ '.tZlZ^ci?^ 


iioa::-— 0— tOOOCl-^OOOOOO 

iOJ — CICOO iCI-O':000t^t^C0 
' CI CI — <M CI C^ ^- CI '— ■ ^- 




o 

s 


• ot^ 

"< 


— 00 = en -.= o o =-. i^ = — t^ ~ ^ "• ■.= <= <M . CO tc CO o n e-> w 

— oo-.rooo-^ — ■rtin — i^ — !M — ococJTco '■gSS'"!2:XJ?:3 


.40 ■ ' '-S* 0000«3-^000 • 

• tci • ■ oi !£>co — oiim>*C ■ 
-^ 1 • "*?• coeo'^cocieoco 






. :o ' ' 'O t— eo 00 --I* 00 Tj> CO > 
t h- 1 -f CO "-r »c '-C ci ■**• i^ 




O 

o 


g^ c^u50Qoo-x)->o^-^~^--^a-^oooa: — ocoo : — — corooo ..J « a5 . .a: ^j- 00 =■- «; c 00 ■ 




..p 


«>coi-i-ot-ooo-.o--cc^<M--5' — -.= -t~o jcsi'Toot- — ^ — — ; ;co o c-. oo » tc i- en . 
^t^cocoin-s^o'dc^woc-i — — "50CCCJIOCO .incoxfocs — -oo • ;co — — moon — — ; 




to 
o 

c 
c 




O -r o -.s c~) -r: r~ CO -.= r- =•- = -■■-;'- 00 >o CO ^ =c : -o oo <m cc -.= -^ 'r ■ ; -.= u- t- co = c>i co - . 




rn 0: (M M =0 CO t- 00 ri 00 a: -J- "5 c-J M cd- :0 ;t- : t- CB C-) — oc — . . ;l- •* t~ <M -»^ -* « ; 
> 1 1 + ++ + ■ + 




or 

o 
o 

c 


jj ^, „ = ,-L-:c;~ju; = .o^<M00t-=M= -< -.= OC OC r- — ^l ^ !M tc ■ ;0 00 cc =^ C-l =^ c-i . 




<• 


(MO-.C — irac>iracOi.-5M-t-t- — "-oocMot- lot^d^t-tMcso-o-* ; ;«5 or- — loiococo . 

C0--C.M^ = «=0-C>OWOOC«C^OO lo-SCOCOCOCOO- ; ;0O 000«-.C-0 ; 




o 

o 




t- .n 00 o 17 - — — — -i- -^ = == "« >" — c^J - "»• '■'' CO o; oo c-i CO r- — 
co^c?S^?S?lSco?^t^icocococ-icocococo?^ .coc-lScoco — co 


• -eo ic c» 00 IC c; 

' 'to i^O iC -f 00 CO ■ 

. . ^.^ 5*3 c^ ^ ^ ^ cv, CO > 










OOCMIO lOOOQOOSCOeoOO 


• loo -^COOOOCOOCi ■ 

' 'i^ cJooo-^oo ! 

; ; 1 +- +-^ : 




^'1 


aooo-^^Mico»cr:cooicc-icot 


— IMCO 
«-— ^-*-, ;y. — .»1-^— ;C"^ — t^. — ..-_ 1 — Cl^l^- — 0000 — 




Clas 


s No.. . 


C) 


















CO 









Oh 
< 



CD 
> 



332 



DIVISION OF MINES AND MINING 



010 



Absorption and linear shrinkage curves for clays of class 12. 
08 06 0^02 I 3 5 7 9 II 13 JS' 



1/ 

^ 20 

1 ° 

^ 20 

% 

'^ 


*-^ 




_Aj 






Na 


6 


















V 




— 














^~ 




_S 


^^ 


-- 


— 


— 


— 


— 


" " 


^ 








_A. 




V^ 


No 


(6 






















^ 








^ 






• -- 


_» 


_S_ 


■ — 


— 


— 


— 


— 


■"■" 








% 






A 






No 


24 












^ 20 
»« 10 
^" 

% 
1 
























- 


\ 


~ 


— 






_S 


„ 


.- 


~~ 




— 


- 














No 


26 
















_A_ 
















^ 






_. 


_S 


-' 


— 


" 


rr 






^ 


1*. 




^ 


~ ~ 


^* 



. . 01008 06 OfO Z / 3 S 7 9 1/ 15 /£■ 



//£AT TREAmfNT IN C0/iE5. 




HEAT TREATnENT IN CONES. 



010 08 06 0^ OZ I 3 ^ 7 9 II 13 IS' 



I 

I 

-J 

I 
I 

i 



20 












He 


'^ 












— 


^ 


A 

























- 


_S 


^^ 


— 


'- 




" 


=^ 


5*, 


— 




?o 








No 


10 













10 


— 


-~ 


< 














/ 






^ 


„ 


Jl 


.- 


:^ 




^ 


— 


•- 


/ 

\ 















?0 


»- 




A 






No 


10 


s 










in 






*^ 


\ 




.^^ 













20 
in 






,s 




,' 


— 


— 


— 


•< 




-^ 




__ 


— 


_A, 


•\^ 




No 


II 


2 
















> 






- 


s. 

















s 


r^ 


— 


— 


— 


> 






- 





HEAT TREATMENT IN CONES. 



52 
-J 



I 



010 08 06 0^ 01 I 3 5 7 9 II 13 IS' 



20 
10 


10 


10 


10 


20 
10 







A 








No 


1 1 


3 














" 


"■" 




— 


— 














S 








_. 


_ ^ 


_ . 


— 


-- 


— 




_ 


A 








No 


II 


7 












.4 




\ 


















■^ 


< 


_ 






No) II 


9 












S 




\ 


< 
















^ 


■X 


""^ 


■^ 




^ 


15 


5 












s 




,, 


« — 


-- 


— 














A 


: , 


S 




No 


17 


S 








































s 


A£- 


^ 


,- 












1 





HEAT TREATHEN T IN CONES. 



CLAY RESOURCES AND CERAMIC INDUSTRY 



333 



Absorption anrl lin<-;tr shrinkago curvis for clays of class 12. 



12 

tt; 

I 

■J 



010 OB 06 Of Ol I 3 5 7 9 // 13 /S" 



CIO 08 06 Of OZ / 3 5 7 9 // 15 /S' 



I 
I 
I 



20 
10 


20 
iO 


ZO 
10 


ZO 
10 















No 


17 


8-1 










— 




_A 
























_S 


„ 


_ _ 


























No 


17 


&-1 










— 




^ 




>>_ 




w 
















S 






^^ 


S 


< 














A 






No 


17 


9-3 


















■""■ 


— 


















$ 




















— , 




^ 






No 


18 



















^ 


^ 


V. 


















J. 


-'*' 


-' 




^ 













HE/\T TREAineN T IN COfiES. 



«^ 10 
>-. 

«2> 

^ 10 

I ^ 

^ 10 

1 » 

*« 10 
•« 

^' 

I 

C; to 
I 



^ 


< 














No 


182 






s 




-• 


Z^ 


•"^N^ 






— 




— 


^ 




\. 






/I 




No 


Id 


3 






s 




\ 


< 


Zl 














= 


A 










\ 




No 


I9|9 






\ 




















s 


^ 


^'' 


Nc 


^ 














^ 


^ 














No 


20|6 






s 




,^»- 


iTT" 














■I* 


A 


7 












No 


2( 


4 




■"■ 


!r 


f 
























< 

\ 
1 





















-y^/jr TREAmENT IN C0IVE5. 



a: 

S 



I 
I 



010 08 06 Of OZ I 3 5 7 9 II 15 IS' 



10 

10 

10 



JO 

o 

30 

ZO 

10 






"^ 


_A 


\ 










No 


21 


6 ' 






_s_ 


• 


<: 


















■*" 




< 










No 


21 


7 










}' 


N 


























^ 


>^ 




No 


22 


1 














_s 


— 


— 


— 


^ 


""" 




















No 


25 


1 
















^ 






-K 


- 








A 












No 


26 


1 








'>> 




\ 


s 


































■- 




— 


— 


s^ 


— 


**^ 


^ 















HEhT TREAjnENT IN COfiES. 



334 



DIVISION OF MINES AND MINING 



i 

ft: 

S 



I 
I 



Alisiirptinn and linear shrinkage curves for clays of class ,„. 

ao 08 06 Of Ol I 3 5 7 9 II li IS- 



010 08 0b Of OZ I Z S 7 9 // 13 /T 



20: 

to- 



20. 
10 



ZO- 
IC 

o 

20- 
10 






^__ 


_A 






No 


7 








— I 


! 














— 


— 


^ 








S 




.. 


^ ^ 


r — 





— 


— 


F— "^ 








A 






Nc 


72 




















■- 


^ 


"~" 


— 


s. 










S 




^^ 


___ 


— 


— 


— 


*' 


"^ 






y 


> 




Si. 


No 


12 


a 




















N 


_- 


_. 




— 




— 




— 


_S_ 


" 


-- 


f^ 












— 


a" 




V 


No 


13 


1 














-\ 


"~~ 


^ 




N 


*- -< 


^- 








_s_ 


,, 


x 
^ 


— 


— 


~~ 


** 




N 


■ 



HEhT TREfiJnENT INCOMES. 



i2 

Ci 10 

5 



^£0 

i 10 
% 

"< 

^ 20 
»« 10 
^" 

I 

f^ 20 
I 



■-^ 




A 


V 




NollT 


1 




r— " 












\ 


S( 
















^ 


«• 


_S 


y 


Jt^ 
















__ 




A_ 






No 


19|8 


















^ 






- 










— 


— 


_s 


— 


— 


-" 


•* 












=" 




A 






No 21 


S 
















— 








5-^ 


^'^ 










S 


^.^ 


s^ 


.• 


— 






N 
















A 




No 25 


6 
























\ 


^ 














_S 


— 


— 


-• 


^"^ 





/y£>}7 TREATMENT INCOMES. 



Ill-B. Dense- Burning. Less Than 6% Apparent Porosity at Vitrification. 

a. With Loxo Vitrificatiox Raxge, \ Cones or Moke. 

14. Mainly Medium to High Strength, But Also Including Some Clays 

of Low Strength. 

No. 10 (p. 163). Riverside County. AlberhiU C. & C. Co. "Hill Blue 
Green." Tliis is a fine-grained, exee.ssively-plastie clay that serves 
mainly as a strengthening clay in sewer-pipe and similar mixes. The 
dry strength is verv high, but the excessive dr^dng shrinkage causes 
serious warping and cracking when used alone. The dry clay is very 
hard and dense. The colors are: drv, 23"'"b; wet, 21'"'; cones 010 
to 06, 9'b ; cones 04 to 1, 9" ; cones 3 to 5, 9"' ; cone 7. 1"' ; cone 9, l""b ; 
cone 11, 13""d (flashed). All test ]iieces cracked on firing, except those 
at cones 010 and 08. Finger-nail hardness is found in the dry state, 
steel hardness is developed at cone 04, vitrification is complete at cone 
1, and bloating begins above cone 5. The total maximum linear shrink- 
age is 22.3'/ , at cones 3 to 5. The softening i)oint is cone 14-15. The 
long vitrification range and excellent dry strength of this clay are its 
princijial merits. 

No. 21 (p. 163). Riverside County. AlberhiU C. & C. Co. "Sagger 
Clay." This is a pink-burning, plastic clay that finds use as a vitrifying 
agent in sagger bodies. It has a smooth, strong ]ilasticity, and a medium 
low dry strength. There is slight effervescence in hydrochloric acid. In 
the dry state it is soft, with a medium-fine grain, and has a tendency 
to laminate. The colors are : drv, 7"b ; wet, 7" ; cones 010 to 04, 5'd ; 
cone 02, 7'd ; cones 1 to 5, 7"d ;" cone 7, 13"'d; cones 9 to 13, 17"'d. 
Iron specks are prominent at cone 7 or above. Finger-nail hardness is 
developed below cone 010, and steel hardness at cone 1. A few small 



CLAY RESOURCES AND CERAMIC INDUSTRY 335 

(Tiii'lss appeared in the test iirin^i, jji-obably cau.sed by too rapid firing 
duriiiji- tlu' water-smokiiijr stajie. Tlie total linear .slirinkajre, plastic 
basis, at cone }'). is 2\.-\' i . The softening point is cone 2."?. The best 
firing i-ange is from eone 02 to cone ^'^. The wide vitrification range of 
this eiay within tlie limits of commercial firing is its principal merit. 
With the addition of non-plastic material, it is suitable for pink- and 
l)uft'-burned face brick, roofing tile, and similar ])roduets, as well as for 
saggei-s. 

A'o. ^^;? (p. 163). Riverside County. Alberhill C. & C. Co. "Yellow 
Owl Cut." This is a yellowish clay containing 12.6'/, of +2()()-mesli 
sai.J, and has good jjlasticity, high drying shriidcage, medium-high dry 
strength, and good dry condition, though with a tendency to laminate. It 
is used in sewer-])i])e mixes. The colors are : drv, 15"d ; wet, 15" ; cones 
010 to 08, 5'd ; cones 06 to 0-1, 7'd ; cones 02 and 1, 9'b ; cones 3 to 7, 7"b ; 
cones 9 to 13, 9""d. Finger-nail hardness is developed at cone 010, and 
steel hardness at cone 1. The total linear shrinkage, plastic basis, is 
1H.6'(, at cone 11, and slight bloating a])i)ears at cone 13. The soften- 
ing i)oint is cone 17. The best firing i-ange is from cone 02 to cone 11. 
The most desirable features of this clay are its dry strength and wide 
vitrification range. 

Xo. 75 (p. 174). Riverside County. Alberhill. L. A. B. Co. "Red 
Xo. 2." This is a vitrifying clay with its light-red firing colors that is 
valuable in roofing-tile and face-brick mixtures. In the natural state 
it is hard and brittle and the color is mottled i)iidv and cream. It con- 
tains 16.4'>v of -(-200-mesh sand. The plasticity is excellent, the dry 
strength is medium, and the dried condition is medium-hard, and 
medium close-grained. The colors are: drv, 7"b ; wet, 7"; cones 010 
to 1, 9'b; cones 3 to 9, 9"b ; cones 11 and 13, l""i (flashed). Finger- 
nail hardness ai)pears below cone 010, and steel hardness at eone 3. 
Absor])tions below lO'^ are obtained at cone 5, and vitrification is com- 
l^lete at coiu^ 11. Slight bloating ap])ears at cone 13, under reducing 
conditions. The fired test pieces are moderately hair-cracked, and at 
cones 11 and 13 a few large open cracks appear. The maximum total 
linear firing shrinkage, ])lastic basis, is 24.0^^, at cone 11. The soften- 
ing point is cone 20-2)]. The best firing range is from cone 3 to cone 11. 
The clay should be mixed with non-plastics to obtain safe firing 
l)roperties. 

No. 123 (p. 56). Amador County. lone (Carbondale). Lea.sed by 
G. A. Starkweather. "Yaru No. 2." This is a red-burning clay with 
smooth and weak ])]asticity. and medium dry strength. It contains 5.4% 
of -|-200-mesh quartz-mica sand. In the dried condition it is soft, fine- 
grained and close-textured. The colors are: dry, 17"d ; wet, 17"b; 
cones 010 to 7, 9' ; cone 9, 9"" ; cones 11 and 13, T''\ Steel hardness is 
developed at cone 02. Less than 10% absoi'])tion a])pears at cone 1. 
The fired structure is sound, and the texture is smootli. Vitrification 
is complete at cone 11, and blistering a])i)ears at cone 13. The maximum 
total shrinkage. ])lastic basis, is 22.1%, at cone 11. The softening j)oint 
is cone 27-28. The best firing range is from cone 1 to cone 11. The 
clay may be used for face brick, roofing tile, red-burned pottery, etc. 

No. 127 (p. 57). Amador County. lone. M. J. Bacon. "Bacon 
Red." This is a red-burning clay with excellent smooth plasticity, 



336 DIVISION OP MINES AND MINING 

and medium low dry strenutli. In tlio dried condition it is soft, and 
fine-grained. The colors are: dry, 7"b; wet, 7"; cones 010 to 5, 9'b; 
cone 7, 7'b ; cones 9 to 11], 7"b. Steel hardness appears at cone 1. Less 
than 10% absorption is obtained at cone 7. The fired structure is 
sound, and the fired surface is smooth. Tlie total lineai- shrinkage, 
plastic basis, at cone 13, is 20.0%. The softening point is cone 27. The 
best firing range is above cone 1. The clay may be used for face brick 
and roofing tile, and for pink colored pottery or tile bodies. 

Xo. 148 (p. 156). Placer County. Lincoln. Lincoln Clay Products 
Co. "No. 8." This is a red burning variety that possesses nearly the 
same plastic, drying and firing i)roi)erties as No. 146, in class 8, but 
with a lower softening ])oint. It contains \2.V/v of -|-200-mesh sand. 
It is used for face brick, sewer pil)e, roofing tile, etc. The colors are: 
dry, 15'b ; wet, 15'b ; cones 010 to 04, f/d ; cones 02 to 3, 7"b ; cone 5, 7" ; 
cone 7, 7"; cone 9, l'"i; cones 11 and 13, V". Steel hardness develops 
at^cone 1. Less than lO^^ absor|)tion is developed at cone 3. The fired 
structure is sound and stony. Blistei'ing is noticeable at cone 11. The 
maximum total linear shrinkage, plastic basis, is 20. 29^, at cone 9. The 
softening i)oint is cone 20. The best firing range is from cone 1 to 
cone 9. 

No. 177 (j). 66). Butte County. Oroville. Quiney road. This sam- 
ple contains a high i)roi>ortion of partly-deeom])osed volcanic ash. 
Since it is the only sami)le of its type on which test data could be 
secured, the results are given as a matter of general interest. The 
plasticity is weak and spongy, the dry strength is medium-high, and in 
the dried condition it is hard, fine-gi-ained, and close-textured. The 
colors are : dry, 17"'f ; wet, 17"i ; cones 010 and 08, 15"d ; cone 06, 13'b ; 
cone 04, 13'd ; cones 02 and 1, 17''i. Steel hardness is developed at cone 
04. The sharp change from 16.8% porosity at cone 04 to 0.1% porosity 
at cone 02 should be especially noted, together with the corresponding 
sharp decrease in volume. The fired structure at cone 02 is glassy, and 
large cracks are present. Bloating and fusion follow when fired above 
cone 1. The total linear shrinkage, i)lastic basis, is 26.6%, at cone 1. 

No. 181 (p. 80). Humboldt County. Angel Ranch. This clay has 
been used by Mr. R. H. Jenkins at the Humboldt State Teachers College, 
as a casting clay for pottery. It has good ]ilasticity, with a tendency to 
stickiness. The residue on 200-mesh is 8.8'/* . The dry strengtli is 
medium high, and in the dried condition it is medium hard, fine-grained, 
and close-textured. The colors are: drv, 17'"f; wet, 17"'b ; cone 010, 
ll'f; cone 08, ll'd ; cones 06 and 04, 9"'d ; cone 02, ll'd; cone 1, 9"i; 
cone 3, ll"i; cone 5, 15". Steel hardness appears at cone 08, and less 
than 10% absorption at cone 04. Vitrification is complete at cone 1, 
and a vesicular structure is developed beyond cone 1. The fired struc- 
ture is sound and stony, and the surface texture is smooth. The maxi- 
mum total linear shrinkage, plastic basis, is 14.0%, at cone 1. The best 
firing range is from cone 08 to cone 1. 

No. 188 (p. 92). Lake County. Kelseyville. This is a red-burning 
thin-bedded clay shale. The clay slakes readil\' in water, and works 
into a smooth and moderately strong plasticity. It effervesces slightly 
in hydrochloric acid. The thy strength is medium, and in the dried 



CLAY RESOURCES AND CERAMIC INDUSTRY 337 

eoiitlitioii it is iiiodiuin Jiard, fine-fjraiiied, and close-textiirtMl. The 
colors are: dry, 17'"f; wet. 17"'i ; oonc 010. 11"; eono OS, 13"; cones 
06 lo 02, })'; cones 1 and 3, 7"k. Steel liardness is developed at cone 
04, and less than 10' r absorption at cone 1. The fii-ed strength is 
medium and a few small cracks are present in all fired test pieces. The 
total linear shrinkage, plastic basis, is 25A% at cone 3. On account of 
excessive shrinkage, sliort vitrilication range, and medium strength, this 
material is only useful for manufacturing a poor quality of common 
brick, even if mixed witli non-plastic material. 

No. 202 (p. 68). Calaveras County. Valley Sjirings. California 
I'ottery Co. ''Pink ^Mottled." This is a fine-grained, red-burning clay, 
with smooth and strong plasticity, and medium dry strength. It con- 
tains AA'/v of -|-200-mesli santl. In the di"ied condition it is soft, fine- 
grained, and clo.se-textured. A strong tendency to laminate was noted. 
Tlie colors are: dry, 11'; wet, 7'i ; cones 010 to 04, 9"b; cones 02 to 5, 
11" ; cones 7 and 9, 9". Steel hardness is developed at cone 02, and 
less than 10% absorption at cone 1. The fired structure is sound, 
tough, and stony. The surface texture is smooth. The maximum total 
linear shrinkage, plastic basis, is 20.6%, at cone 11, and bloating is 
apparent at cone 13. The .softening point is cone 20. This is an excel- 
lent face brick and roofing tile clay. 

No. 203 (p. 68). Calaveras County. Valley Springs. California 
Pottery Co. "Yellow Plastic." This is similar in its ceramic prop- 
ci-ties to Xo. 202, but is not so fine-grained, and contains more non- 
plastic matter. The residue on 200-mesh is 10.2%. The colors are: 
dry, ir)"b; wet, 15"b; cones 010 to 04, ll'b; cone 02, 9'; cones 1 to o, 
11"; cone 7, 7"; cone 9, 5". Steel hardness is developed at cone 1, and 
less than 10% absorption at cone 5. The surface texture is rougher 
than that of No. 202. The total linear shrinkage, plastic basis, is 
18.0%, at cone 13. The softening point is cone 19-20. 

No. 210 and 212 (j). 186). Sacramento County. Xatoma. Xo. 210 
is a sample of ''Xatoma Xo. 1," and Xo. 212 is a sample of "Xatoma 
No. 3." They differ onl}' in the proportion of non-plastic matter, which 
is greater in X"o. 212 than in X'^o. 210. The clay is extremely fine- 
grained, and contains a high i)roportion of mica. The jilasticity 
is strong, and in the dried condition the samples have finger-nail 
hardness, are fine-grained, and close-textured. The clay must be 
dried carefully to avoid cracking. The dry strength of Xo. 210 is 
high, and of Xo. 212 is medium liigh. The colors of Xo. 210 are: dry, 
13"b; wet, 13"i; cones 010 to 04, 9'; cone 02, 9'i; cones 1 and 3, 9k; 
cone 5, 9'm. The colors of X^^o. 212 are: dry, 13''; wet, 11"; cones 
010 to 06, 13" ; cone 04, 7" ; cones 02 to 3, 7"i ; cone 6, 5"m. Steel hard- 
ness and less than 10% absorption are developed at cone 04, and vitrifi- 
cation is complete at cone 5. A vesicular structure appears at cones 7 
to 9. The fired structure is sound and strong and the .surface texture 
is smooth. The total linear shrinkage, plastic basis, of No. 210 is 19.1%, 
at cone 5, and of X'^o. 212 is 16.9%, at cone 6. 

Mr. L. W. Austin, of the company, kindly gave the following data 
on Xo. 210 : 

22—54979 





Equivalent 


Acciinnil 


Si/.v in imn. 


mesh 


on 


0.02 


1.000 


0.40 


0.01 


2,000 


2. OS 


O.OOU 


3,000 


7.0G 


(1.(104 


4,000 


13.36 


o.oo:! 


5,000 


20.19 


0.002 


10,000 


29.89 


0.001 


20,000 


52.07 


0.000(1 


30,000 


59.22 



338 DTVTRTON OF MINES AND MINTNfi 

Sizing Test of Natoma Clay No. 1. 

{{\\v Percent 

through 

99.60 
97.97 
92.94 
86.64 
79.81 
70.11 
47.93 
40.78 

]\ri'. Austin ro])orts the results of commercial firiiio' tests on Natoma 
No. 1 (our number 210) as follows: Drying shrinkage, 7.5 to 9.0%; 
total linear firing shrinkage at cone 5, approximately 15% ; absorption 
at cones 5 to 7, 0.35 to 0.1% ; bloating usually begins at cone 9. Another 
firing test gave a total linear shrinkage, plastic basis, of 20. 5^^, after 
heating to cone 5 in 36 hours and holding the finishing temperature 
for 4 hours. 

A number of clay products manufacturers have tested this clay, and 
some have introduced it into their mixes. It is particularly valuable 
for the purpose of producing a hard, strong vitrified body, with rich- 
red colors, and a smooth texture. In some plants the sviccessful use of 
this clay will require a modification of the drying procedure. The 
clay can be cast, or pressed, and takes die impressions very perfectly. 
In an auger machine, the finely divided mica is an aid to lubrication, 
yet the flakes are not so large as to cause excessive lamination. 

b. With Short Vitrification Range, Less Than 4 Cones. 
15. Medium to High Strength. 

No. 1 (p. 218). Santa Barbara County. R. Muengenberg and E. 
11. Whitiker. West Montecito Street, Santa Barbara. This is a mixture 
of a yellowish sandy clay and a plastic black adobe, mined locally and 
used for structural wares. It effervesces .slightly in hydrochloric acid. 
It develops a sticky plasticity and has high dry strength and good dry 
structure. The percentage of -f--^^0-i^i<^^li sand is 33.2. The dry color 
is 17"", the Avet color is 17""i, and the fired color to cone 3 is 9'i, a 
good color for common brick. Steel hardness is developed at cone 1, 
and bloating appears at cone 5. The maximum total linear shrinkage, 
plastic basis, is 12.8% at cone 3. The best firing range is from cone 
02 to cone 3. 

No. 2 (p. 218). Santa Barbara County. Toro Canyon, near ]\Ionte- 
cito. An adobe clay, used in the Toro Canyon brickyard operated by 
jMuengenberg and Whitiker for the manufacture of red structural 
wares. The percentage of -|-200-mesh sand is 33.4. It develops a sticky 
plasticity and high dry strength with good (\vx structure. The dry 
color is 13"' and the wet color is 13'"i. The fired color is 9'i from 
cones 010 to 02, and 7"i from cones 1 to 3, both of which are good 
common brick colors. Steel hardness is developed at cone 1, and 
bloating appears at cone 5. The maximum total linear shrinkage, 
plastic basis, is 12.5% at cone 3. The best firing range is between cones 
02 and 3. 

No. 4 (p 234). Ventura County. A yellow plastic clay from the Fer- 
nando (Pliocene) formation, north of Ventura, and used by the People's 



CLAY RESOURCES AXD CERAMIC INDUSTRY 339 

LuiiilxT Co. for tlio mamit'aeture of ml si i-iirliii;il ware. It is finc- 
^raiii(>(l. and <l('V('l()|)s sticky plasticity and liiiili di-y strcii<:tii, l)ul lias 
a lii^^h dryiiiji' slirinka<.;c and a tendency to warp wiien nscd alone. It 
contains hut lA'/c of +2()()-mesli sand". The dry color is 17"'b, the 
wot color is 17'", and liie tired colors are i)'I) from cones 010 to 06, 9' 
at cone 04, and !)'i fi'oin cones 02 to 1, <;ivin<;' an excellent i-anjre for 
conuuon brick, building' tile, and roofing tile. Steel hardness is 
developed at cone 02, and bloating begins above cone 1. The maximum 
total linear shrinkage, plastic basis, is 21.4%, at cone 1. The best firing 
range is from cone 04 to cone 1. The high shi-inkage should be 
reduced with non-i)lastic material for best results in nuiking .structural 
ware. 

No. .-) (|). 234). Ventura County. A grayish blue plastic clay over- 
lying No. 4. Used principally for oil-well mudding, and with clay 
Xo. 4 in the manufacture of structural ware. The ceramic ])roperties 
are similar to those of sample Xo. 4. The dry color is 21""b, the wet 
color is 21"", and the fired colors are 7"b from cone 010 to cone 04, 
.I'd at cone 02, 7" at cone 1, and 13"'i (flashed) at cone 3. Knife 
hardness is develoi)ed at cone 02, maximum shrinkage at cone 1, and 
bloating begins near cone 3. The maximum total linear shrinkage, 
plastic basis, is 20.0%, at cone 1. The best firing range is from cone 04 
to cone 1. For best results, the clay should be mixed witii non-plastic 
material for manufacturing structural ware. 

No. 6 (p. 234). Ventura County, 2.7 miles north of Santa Paula. A 
yellowish plastic clay used for making dry-pressed common brick in 
the yard of Anderson and llardison. Jt contains 17.8 y^ of -[-200-mesh 
sand and develops good, but sticky, plasticity, and high dry strength. 
Tiiere is slight effervescence in hydrochloric acid. The dry color is 
17"'b, the wet color is 17"'i, and tlie fired colors are 7'b from cone 
010 to cone 02, 7" at cone 1, and 7"i (flashed) at cone 3. These are 
good red brick colors. Knife hardness is developed at cone 02, and 
slight bloating is apparent at cone 3. The maximum total shrinkage, 
plastic basis, is 17.5 /V , at cone 1. The best firing range is from cone 
04 to cone 1-|-. The wide vitrification range, from cone 02 to cone 3 — , 
coupled with other desirable (lualities, make this a good clay for hard 
burned structural w^are. 

No. 30 (p. 203). San Diego County. Rose Canyon. San Diego Tile 
and Brick Co. This is a vellow and grav Tertiarv clav shale, used for 
making common brick and hollow building tile. It effervesces slightly 
in hydrocldoric acid. It contains lii.O'r of -|-200-mesh sand, has good 
plasticity for either the auger or the brick-press, medium high dry 
strength, and a good dry structure. It can be dried rapidly without 
danger of cracking. The colors are: drv, 21""; Avet, 17""; cones 010 
to 04, 9'd; cones 02 and 1, 9"; cone 3,' 9"' ; cone 5, 9"'i. The fired 
colors cover a good range of desirable common brick reds. Finger-nail 
hardness is present in the dry state, and knife hardness appears at 
cone 1. Vitrification is complete at cone 3, and bloating begins at 
cone 5. The fired brick are hard, dense and sound. The maximum 
total linear shrinkage, plastic basis, is 16.4%, at cone 3. The best firing 
range is from cone 010 to cone 3, and excellent hard-burned brick are 
obtained from cone 1 to cone 3. 



340 DIVISION OP MINES AND MINING 

No. o/ ()). 204). San Die«ro County. Rose Canyon. Union Brick Co. 
An unconsolidated j^elloAvisli sandy-clay of Tertiary a«:e. The forma- 
tion contains pcbhles and bonldors, the larprer part of Avhicli are removed 
by screening. The sample contains :>2.(i', of -]-200-mesh sand. It is 
used for common brick, but is suitable also for making liollow building 
tile. The plastic and drj^ing properties are such that it can be used 
alone. It has a higli dry strength, and in the dry state it is hard, with 
a medium grain and open texture. The colors are: dry, 17'"b; wet, 
13'"i ; cones 010 to 02, 9'i ; cones 1 and 3, 7" ; cone 5, 9''i. These are 
nearly the same as in sample No. 30, and cover a good range of common 
brick colors. Finger-nail hardness is present in the dry state, and steel 
hai'dness appears at cone 1. Vitrification is complete at cone 3, and 
l)loating appears at cone 5. The maximum total linear shrinkage is 
10.4% at cone 3. The best firing range is from cone 010 to cone 3, and 
Avell vitrified products are obtained from cone 1 to cone 3. 

No. 42 (p. 181). San Bernardino County. Vidal. "Blue." See also 
No. 43. This is a bluish, extremely fine-grained clay-shale of the ben- 
tonitic type. In water, it slakes readily to a smooth slip. It effervesces 
strongly in hydrochloric acid. When mixed with 57.7% water, it devel- 
ops a smooth, workable plasticity, without excessive stickiness. The 
drying shrinkage is high, and ordinary air-drying methods caused 
large drying cracks and excessive warping to develop. In the dried 
state, it is hard, fine-grained, brittle and close-textured. The dry 
strength could not be determined accurately. With the firing schedule 
emplo.yed, the clay was badly shattered, but data were obtained for 
cone 010 and cone 08. The colors are: dry, 17"'f; wet, 21'"d; cones 
010 and 08, 15"b. Finger-nail hardness appears in the dry state, and 
steel hardness at cone 010. In view of the isolation of the deposit, it 
has no commercial A'alue. The fineness of grain, plastic strength, and 
apparently high dry strength are interesting features. No tabulated 
data or charts of firing shrinkage and absorption are presented. 

i\^o. 45 (p. 181). San Bernardino County. Vidal. "Pink." This 
clay is similar to No. 42, except that it contains more iron and more 
non-plastic matter, resulting in deeper fired colors, and lower drying 
and firing shrinkage. It effervesces strongly in hydrochloric acid. 
The dry strength is high. The colors are: dry, ll'f ; wet, 17""d; cones 
010 to 1, 11"; cone 3, 13"k. Efflorescence is especially pronounced. 
Finger-nail hardness is present in the dried state, and steel hardness is 
developed at cone OS. At cone 3, kiln-marking and bloating begins. 
The maximum total linear shrinkage, plastic basis, is 20.0%, at cone 1. 
The fired structure is tough and strong. The best firing range is from 
cone 08 to cone 1. 

No. 60 (]). 100). Los Angeles County. Los Angeles. Davidson Brick 
Co. This is a red-burning clay suitable for the manufacture of com- 
mon structural ware. The ratio of clay to sand is such that the plas- 
ticity, drying and firing properties are entirely satisfactory without 
admixture with other materials. It contains 5.4%, of +200-mesh sand. 
There is slight effervescence in hydrochloric acid. The dry strength is 
medium-high, and the dry structure is hard, fine-grained, and open- 
textured, with a tendency to laminate. The colors are : Avy, 17"d ; wet, 



CLAY RESOURCES AND CERAMIC INDUSTRY 341 

]7'"i • cone 010 9'(1 ; cone 08, ll'b ; cone OG, U'b ; cone 04, 9"b ; cone 02, 
!"• cone 1, 9"'; cone 3, 5'"i ; and cone 5 (bloated) 9"'k. This affords 
an 'excellent range for red brick. Finger-nail hardness is obtained 
below cone 010, and steel hardness develops at cone 1. Vitrification 
is complete at cone 3. and bloating begins just below cone 5. All fired 
test pieces were sound and strong. Tiie maximiiin total linear shrink- 
age, plastic basis, is I6.97; , at cone 3. Tlie best firing range is from 
cone 010 to cone 3, or if vitrified products are desired, from cone 1 to 
cone 3. 

Xo. 61 (p. 102). Los Angeles County. Santa :Monica. (Jladding, 
McBean and Co. This is representative of tlie clay used, by several 
other plants in the same locality, and in some of the sewer-pipe and 
conduit plants in the Los Angeles district. It is a red-burning clay, 
witli suitable plastic, drying, and firing properties to permit its use 
as the sole ingredient of common brick, hollow building tile, roofing 
tile, etc., and as a vitrifving and bonding clay in sewer-pipe and elec- 
trical conduit mixes. It contains 18.07o of -f 200-mesh sand. The dry 
.strength is medium liiu'h. and the dry condition is hard, fine-grained, 
and close-textured. Tlie colors are: dry, 17"'; wet 13''"k; cone 010, 
ll'b: cone 08, 11' ; cones 06 and 04, 9' ; cone 02, 9'i; and cones 1 and 3, 
9"k. These colors give a suitable range for the uses indicated above. 
Finger-nail hardness is obtained below cone 010. and steel hardness at 
cone 02. Vitrification is complete at cone 1, and bloating begins at cone 
3. The fired structure is sound and strong. The maximum total linear 
shrinkage, plastic basis, is 13.1 7r, at cone 1. The best firing range is 
from cone 010 to cone 1, or if vitrified products are desired, from cone 
02 to cone 3. 

.V^;. 89. Riverside County. Elsinore. Hudson Ranch clay. This 
is a red-burning sandy clay from an undeveloi:)ed deposit. It effervesces 
slightly in hydrocliloric acid. It has good plasticity, medium-high dry 
strength, and the dried condition is hard, medium fine-grained, and 
close-'textured. The colors are: dry, 17""b; wet, 17""; cones 010 to 
06, 15"b; cones 04 to 1, 13"b ; cones 3 and 5, 7''; cones 7 to 13, 7"k. 
Finger-nail hardness is present in the dried state, and steel hardness 
is developed at cone 7. Ab.sorptions under lO^r are obtained at cone 
11, and bloating is well developed at cone 13. All fired test pieces are 
sound. The maximum total linear shrinkage, plastic basis, is 20.2% at 
cone 11. The clay might have local use as a coloring and bonding clay, 
but its high shrinkage and short vitrification range are undesirable 
features. 

No. 118 (p. 192). San Benito County. Paicines. This is a yelloAvish, 
plastic surface clay, with a smooth, strong ])lasticity and exceptionally 
high dry strength! There is slight effervescence in hydrochloric acid. 
Tn^the dried condition it is hard, fine grained, and close textured. It 
contains 4.0^; of -l-200-mesh sand. The colors are: dry, 21""d ; wet, 
21""; cone 010, 9'd : coups OS and 06, 9'b; cone 04, 9'; cones 02 and 1, 
9'k; cone 3, 7"k. Finger-nail hardness is develoi^ed below cone 010, 
and steel hardness at cone 04. Less than 10% absorption is developed 
at cone 04, and vitrification is complete at cone 02, above which temper- 
ature bloating begins. The fired structure, up to cone 02, is sound and 
stony. The maximum total linear shrinkage, plastic basis, is 18.8%, at 



342 DIVISION OF MINES AND MINING 

cone 02. This clay is not in use, but would be entirely suitable for red- 
burned structural ware, and is worthy of investigation as a casting clay. 

No. 172 (}). 136). Nevada County. ]\Ianzanita ]Mine, near Nevada 
City. This is the so-called "pipe clay" of the hydraulic mines. It 
develops fair plasticity, medium-high dry strength, and a medium-hard, 
fine-grained and open-textured dried condition. The colors are: dry, 
grayish white; wet, 28'""d; cones 010 to 04, 15"b; cones 02 to 3, ll"b; 
cone 5, 5"i ; cone 7, 5"k. Steel hardness is developed at cone 04, and 
less than 10*^^ absorption at cone 02. The fired structure is sound and 
stony, and the surface texture is slightly rough. Tlie nuiximum total 
linear slirinkage, plastic basis, is 24.8% at cone 5. Bloating is apparent 
at cone 7. The clay could be mixed with non-plastics and used locally 
for the manufacture of common brick. 

No. 184 (p. 80). Humboldt County. Eureka. Freshwater Slough. 
This is a common clay with good plasticity, and medium high dry 
strength. In the dried condition it has finger-nail hardness, is fine- 
grained, and close textured. The colors are: drv, 17""b; wet, 17""i ; 
cones 010 to 06, 13'b ; cones 04 and 02. ll'b; cone 1, 13'k. Steel hard- 
ness is developed at cone 04, and less than 10' { absorption at cone 02. 
Vitrification is complete at cone 1. The fired structure is sound, and 
the surface texture is smooth. The maximum total linear shrinkage, 
plastic basis, is 22.8% , at cone 1. The clay is entirely suitable for the 
manufacture of common brick, hollow tile, and roofing tile, but should 
be mixed with non-plastic material to decrease the shrinkage. 

.Vo. i(95 (p. 80). Humboldt County. Eureka. Loofbourrow Ranch. 
This is a common clay with sticky plasticity, and medium-high dry 
strength. It is extremely fine-grained and contains carbonaceous 
matter. In the dried condition it has finsier-nail hardness. The colors 
are; dry, 15'""b ; wet, 15'""i; cones 010 to 04, ll"b; cone 02, .5"; 
cone 1, 7"m. Steel hardness and less than 10% absorption are devel- 
oped at cone 02, and vitrification is complete at cone 1. The fired 
structure is sound. The total linear .shrinkage, plastic basis, is 19.3%, 
at cone 1. 

No. 200 (p. 73). Contra Co.sta County. Walnut Creek (Oxley 
siding). N. Clark & Sons. This is a red-burning, calcareous shale 
that is used as a non-plastic ingredient in sewer-pipe mixtures. The 
plasticity is weak, the dry strength is medium, and in the dried condi- 
tion it is medium hard, fine-grained, and open-textured. The colors 
are: dry, 17"'f; wet, 17"'b; cones 010 and 08, 15"b ; cone 06, 11'; 
cones 04 and 02, 9'; cone 1, 9'k; cones 3 and 5, ll'ni. Steel hardness 
and less than 10"^; absorjition are developed at cone 1. The fired 
structure is fine-granular, and the surface texture is slightly rough. 
Above cone 1, the test pieces are disrupted by one or more large cracks, 
and the greenish-broAvn coloration due to the presence of lime is 
a])parent. Tlie maximum total linear shrinkage, ])la.stic basis, is 19.7%, 
at cone 3. 

No. 211 ()). 81). lliiiiil)()ldt Comity. Near Strong's Station, Van 
Duzen River. This is a common-l)rick clay tliat has good pla.sticity, 
medium-high dry strength, and in tlie dried condition has finger-nail 
hardness, is fine-grained, and close-textured. The colors are : dry. 



t'LAY RESOUKCES AXD t'EHA.MR' INDUSTRY 343 

21""d; wet, 21""b; cones 010 and 08, 13"b; cones 06 to 02, 11"; cones 

1 and 3, 5"". Steel liardncss and less Hum lO'r absorj^tion a|>]iear at 
cone 1. The fired strncture is sound and stronj>', and the surl'ace texture 
is slig:htly roufrli. The total linear shrinkage, plastic basis, is 15.1%, 
at cone 3. The material could be successfully used for the manufacture 
of common bi-iek and hollow tile, although the fired colors are not 
especially atti'active. 

No. 223 (p. 141). Oranue ("ounly. ({oat Ranch. (J., McP.. tk Co. 
Red-burning -shale. Tliis material develops good plasticity if ])roi)erly 
ground and jiugged. The dry strength is medium-high, and in tlie 
dried condition it lias finger-nail li;ii-dness, and is close-textured. 
Tlu're is sliglit effervescence in livdrocldoric acid. The colors are: dry, 
ir/'d; wet, 17"k; cones 010 to 06, 13"b; cones 04 and 02, 11"; cone 1, 
o"\; cone 3, 5"k ; and cone 7. y'm. Steel liardness and less than 10% 
absor])tion are developed at cone 1, and bloating a])i)ears at cone 5. 
Tlie fired structure is sound and strong. Tlie maximum total linear 
slirinkage, plastic basis, is lA.b'/c, at cone 3. This is an excellent 
material for the manufacture of vitrified heavy clay products, such as 
sewer pipe, electrical coiuluit, paving- brick, and similar ware. 

No.264{]).A2). Alameda County. Decoto. M & S Tile Co. This 
is a common alluvial clay that is used for making hand-made roofing 
tile. The plasticity is good, the dry strength is high, and in the dried 
condition it has finger-nail hardness, is fine-grained, and close-textured. 
The colors are: dry, 17"i ; wet, 15"k ; cones 010 and 08, 11'; cones 06 
and 04, 9'i ; cone 02, 7'k. Steel hardness and less than 10'/ absori)tion 
are developed at cone 02. Bloating begins above cone 1. The fired 
structure is sound, and the surface texture is smooth. The total linear 
shrinkage, plastic basis, is 14.27' , at cone 02. This clay belongs to the 
same geologic formation as No. 265, and its ceramic pro])erties are 
closely similar. 

No. 265 (p. 40). Alameda County. Niles. W. S. Dickey Clay Manu- 
facturing Comi)any, Plant No. 18. This is a common alluvial clay that 
is used for manufacturing hollow tile and paving brick. The i)lasticity 
is fair, but it is usually necessary to add from 15 to 20^ of a ])lastic 
clay from Lincoln or lone to secure suitable working i)roperties for an 
auger machine. The dry strength is medium high, and in the dried 
condition it is hard, fine-grained, and close-textured. The colors are: 
dry, 15"i ; wet, 13"k; cones 010 and 08, IT ; cones 06 and 04, 9'i; cones 

02 and 1, 9'm. Steel hardness and less than lO^' absorption are 
develojied at cone 02, and vitrification is complete at cone 1. The fired 
structure is sound and strong. The total linear shrinkage, plastic basis, 
is 14.0%, at cone 1. 



344 



DIVISION OF MINES AND MINING 



TABLE No. 26. 

III. Red-Burning Clays. 

B. Dense-burning-. Less than 6% apparent porosity ;it \itrificatiun. 

a. With long vitrififation i-ange, 4 cones or more. 

14. Mainly medium to high strength, but also including some clays of low strength. 

















Soften- 


Clay 














ing pt. 


No. 


% S.W. 


% P.W. 


% W.P. 


D.T.S. 


% D.V.S. 


% D.L.S. 


In cones 


10 


3G.0 


10.5 


46.5 


1530-1- 


73.4 


20.0 


14-15 


21 


13.5 


21.7 


35.2 


187' 


23.3 


7.2 


23 


22 


23.5 


14.8 


38.3 


525 


45.0 


13.0 


17 


75 


16.6 


21.7 


38.3 


292 


28.7 


8.7 


20-23 


123 


19.2 


23.2 


42.4 


228 


31.0 


9.4 


27-28 


127 


16.9 


20.7 


37.6 


121 


28.8 


8.7 


27 


148 


15.9 


19.3 


35.2 


255 


28.1 


8.6 


20 


177 


22.1 


39.7 


61.8 


582 


26.4 


8.1 




181 


14.2 


12.3 


26.5 


794 


28.6 


8.6 




188 


25.1 


31.7 


56.8 


364 


36.2 


10.8 




202 


17.5 


21.5 


39.0 


230 


29.4 


8.9 


20 


203 


15.3 


18.6 


33.9 


232 


27.1 


8.2 


19-20 


210 


21.5 


15.5 


37.0 


1009 


40.3 


12.0 




212 


18.9 


16.3 


35.2 


625 


35.0 


10.5 





h. With short vitrification range, less tlian 4 coni's. 
15. Medium to liig-h strength. 























Soften- 


(May 




















ing pt. 


No. 


% S.W 




% PW. 




% W.P. 


D.T.S. (A 


D.V.S. 


% D.L.S. 


in cones 


1 




14.0 




13.1 




27.1 


848 


27.8 


8.5 




2 




12.0 




11.9 




23.9 


845 


24.4 


7.6 




4 




29.4 




17.8 




47.2 


1212 


54.0 


15.5 




5 




22.1 




18.3 




40.4 


]0;!4 


39.7 


11.8 




6 




22.2 




13.7 




35.9 


1258 


43.5 


12.8 




30 




15.3 




19.5 




34.8 


595 


27.3 


8.0 




31 




6.4 




13.5 




19.9 


903 


12.5 


4.0 




43 




30.4 




16.7 




42.7 


1158 


59.4 


16.8 




60 




14.2 




18.7 




32.9 


720 


25.1 


7.8 




61 




11.4 




14.2 




25.6 


639 


22.0 


6.9 




89 




27.5 




13.9 




41.4 


597 


52.4 


15.0 




118 




26.4 




13.1 




39.5 


1363 


53.2 


15.3 




172 




16.6 




41.0 




57.6 


352 


20.0 


6.3 




184 




26.4 




20.9 




47.3 


703 


43.8 


12.9 




185 




18.7 




21.4 




40.1 


502 


31.2 


9.4 




200 




14.7 




2 8. 3 




43.0 


363 


21.8 


6.9 




211 




14.2 




16.5 




30.7 


619 


26.1 


S.O 




223 




10.2 




16.8 




27.0 


412 


18.5 


5.8 




264 




15.6 




10.8 




26.4 


1020 


31.8 


9.6 




265 




12.5 


Per 


12.4 
cent shrill 


24.9 
kage water. 


791 


25.2 


7.8 




% 


S.W. 




% 


P.W 


i^ 


Per 


cent pore 


water. 










W.P 


== 


Per 


cent water of 


plasticity 










D.T.S. 


=r 


Dry 


transverse 


Stl 


ength, pounds per square incli 


williout sand. 


% D.V.S. = 


Dry 


ing shrinkage, 


per cent 


dry volume. 









% D.L.S. 



CLAY RESOURCES AND CERAMIC INDT'STRY 



345 



5 B 



V .^ K UJ 



^ c - ■ — ■ 





u 

en 

c 


P 


C 
I-. 


o 


s 




Z 
UJ 


c 

3 

CO 

1 

■a 




.2 




c 


p 


-1 

CO 


n 




^ 




e 


K 


IC 


j= 




bC 




r3 






CO 


M 


u 


> 


^ 






•"■ 


o 


j=: 


1- 
o 


»o 



2 a S -^ 

.2 ^ 



o 



o 

o 



o 
O 






s°: 



d CO c^ >o Oi cc 



O'^CO'-'C^O 



CO o o (^ »o "O r* 



I 

•00 



CO O O t^ CI C-J • 






^- c; cc CO c^i c>i CO 

C^ O T^ t-^ »0 O -* 



•b-CO 
.CD CO 



00 OOOOO O T-lOO 



'CO<M 






O O Ci 53 CO t* O 



^ ic »o rr O O Tt" 



• eoi— ' 
iroci 



<^H I-"** OCO CD 



n^ I -^D OO t^ O -^ 00 OO 

-< \ (N^Ci'— C^*-"' '7". ?^. "^ 



>^00 'OO 



,o^ 



OO CD 00 >— ' !>■ O (M 



■ CO O CD t^ CO ^ 

I C^ — lO d lO lO 
I CO C^l (T-l (M "-< 
•f4-+^- 



^ . -^ 



O I t CD 
OS ' ' t-t 



to^ 



«5^%OOOCMCDOI locDt-'S'Cv^LO OiOO .C^iOt-t-.-<rt.l-.OOaOO 



t^ 



1 CO — • lO 
I CC OO CO 






OCOOOOC^'-COOr^ .a:-^l^(Mrt^»0 (MOO .OCOiOOt^' 

r^t^yDO;50oo-^t^»cr^ 



CO CM CO — < (N <M M (N »-" ^ ^^ ^ ^ cN 



1— .'^oo — coomi^ 



cjoor^'j'-a-ouso'o-* — els'*— " to — -"ncoo^n'-ococM 



Tf40C:3: ;DCOCOC005CD(MOCO'M 

00"*"^D:"^»(Or— oooco-^cocoo 
eo<>icoeoco*M co-^tM-— 'C^ 



OcDC^>D<M00C000C0iO»OCiO'0:D00cDcDQ0-r 

:DCO(M'-'»CCO"^i«C^IcDOO^OO(MCO'^QO»£3COCO 
(7qC-l^H<Mf—C^<M(MCO>— iW i-t<-ti— 'COOlC^ •— 



OO-HCCM^rS-CDC^iOCn-^^C^cDOO M^C5^lOeOOCnt-Oi — CRC^COt^^-OOCOOJO: 






..» 



ooo — — ooooO(Nt^te — r- — t- cOT)<iooico<Ne<it~;0^c<i«o->»'Oc^io«(NO:» 

»-;reto(Mt^co«;C'i'XJooirtr^t>jo doodr^io-* ocoiN to -* -;oo 2; 2°'"'^ "* " 

t-(M>OC-. « to -*-£-<• to Ot--*-* c^-»-ir:c-lC^)C~ltOiOQO0O — -tf-OC^OOCOCOOO-T^ 



otocsMMooocntocot-cor-woo <nco — -^cooco-.o — cocootoi-ootoo-.tr-o 



+ 



^W-^tDOOOtD-l-tO-l- — 0000 — CO00f-tOt~00-»'<M-J<---.t~(MM- — OtOI~c= 
CN— CI— 00 — O'*0000t0 00 — "5 — (MTjCICOCOiOr-. 

SSS^ §i!MS«jScoc^<Mco<McoiM>racoco-rcoco<M'M 



COOOCOCOOOt-5^=ltOOUO>CO^ OOira-3>tO — OtOCOiO — OC-. -•I-Q0-*0 — cote 
^,-_H-^-.^tO<MtOtOC^O-^ O^-^^COOOCMOOO^CC-^-riMO-OO 



Cl; 1 OtOOO — IM-COOtOC-l-J'— MQOOO ^cr.QOr-"5m050«OOOU500000-.l- '!<'»;'*; <M 



!=■, OTOooOMcr-c-iocsoitcoo coioiocsitotocoooMoo — irjo — m — ooocotc 
.toin — ^co a^^^Q^ooc^oa^'-sim-mooao 



C0»000"t oc<»»c- 



1 I 






,— ^-— .— —•.— (M<MC^(M 



Class No. 



+ 
to 






I] 

Oh 



II 



346 



DIVISION OF MINES AND MINING 



Absorption and linear shrinkage curves for clays of class 14. 



i2 

I 
i 

I 

-J 



5 

I 

I 



010 OBOb Oj OZ.I 3 S 7 9 II 15 IS' 



010 08 Ob Of OZ I 



20 
10 



20 

10 



eo 

10 



20 

10 















No 


10 














A 
























S, 


-- 


>«Si 


— - 


-- 





> 


*^ 


X 








A. 




\ 




No 


21 




















^ 


"V 


►"^ 


^. 


•»•• 


— 


— 




.- 


.S_ 


— 


-.-' 


^^ 








^ 


— 








A 








No 


22 


















X 


X 


















S_ 




•• "■ 




— 


^^ 


■*■ 


■*■ 


- 


^ 






A 




^ 


<^ 


No 


75 


























\ 


^ 


— 


— 


,*' 


<«« 




— 


_S 


-- 


— 


-" 








'"v 


\ 







7 9 II 13 /S 



HEPCT TREATMENT IN C0NE5. 




HEfiiT TREATHENT IN CONES. 



010 OB 06 O'tOZ I 3 5 7 9 H 13 IS" 






ft: 

i 

-J 



30 

20 

/O 

o 

10 

10 



-10 

zo 

20 
10 





\ 


A 








No 


17 


7 




T~~ 








\ 
























> 


^— 


< 


















x' 


'S 




\ 




























He 


Id 


1 










N 


/\ 


- 






















_s. 


> 


^ 


— . 


V 
























\ 












^^^ 


vA 








Nc 


-IS 


& 












s 


^ 


N 




























... 














-. 


s. 


-- 


"'^ 


\ 

















go 08 Ob Of OZ. I 3 5 7 9 // /J XT 



^EAT TREATMENT IN CONES. 




HEAT TREATMENT IN CONES. 



CLAY RESOURCES AND CERAMIC INDUSTRY 



:U7 



tt: 

i 

-J 



I 
I 



Absorption and linear slirinkape turves for clays of class 15. 

iy0 08 06 Of OZ / 3 5 7 9 II 13 /T 



Vl 


















— r 
No 


1 










A 


— 




s. 


















■" 






s 








^ 


< 
















(^ 














No 


Z 






10 


10 


ZO 

to 


10 












s 






S 


X 


-• • 












' — 


>A 


^ 


V 








No 


4 








,s. 


., 


> 


S 


















A 














No 


5 








"~" 


— 


N 
















• 




_s_ 


,. 


^^ 


'X 


"^ 














- 


^ 





s. 










No 


6 






^ 


X 


,« 




^ 


1 












_ 



OlOO&Ob CH OZ I 3 S 7 S II 13 IS" 

^ zoY 

■^i 10 

s 



0^ — 



ft: 
^ 10 

|c 
-J 

^ CiO 
•» 

§" 10 

to 

I 

^ 10 



/f£AT TREAjn^NT IN COfiES. 





-, 


A 












Nd30 








\ 


V 




















S_ 


^' 


>< 


N 


*-* 
















A_ 


^ 


s 








Nc3l 
















S 




s 

* 


^ 


^ 
















A 




\ 








No|43 
















_S 




> 


<; 


















A 












Na60 














\ 




















S 


^^ 


— ^ 


K 
















A 


s 










No|ei 
















s^ 




^ 


^^ 















OU-J-—; 



^£/?7 TREATMENT IN C0NE5. 



OI0080(>0fOZI3579 II 13 IS 




010 08 Ob Of 02 I 3 5 7 S II 13 IS" 



HEAT TREATMENT IN CONES. 



-J 



I 

I 



30 
20' 
10- 


JO- 
20 

10 
O- 

30: 

20- 

10 













No 


18 


4 












A 


























\ 


V. 


r*** 


















JS 


..' 


x 


\ 


























No 


16 


5 












A 


























^ 


V 




















_S 


-'* 


/s 


\ 



















A 








No 


20 











— 










\ 


^^ 


*V 










— 




^ 


— 


^^ 


/ 

X 


\ 


^ 








J 





'HEAT TREATMENT IN CONES. 



348 



DIVISION OP MINES AND MINING 



Absurption and linear shrinkage curves for olays of class 15. 
010 Ob Ob (HOI I J 5 7 9 II 15 IS- 



-2 

oc) 20 






A 






No2l 


1 




1 






>-> 
"m /o 








^ 


\ 
















%zo 






S. 


^ 


\ 


•• ■• 














- 




A 






No 


£2 


3 












^ 




V 




/ 


/ 














_s 


-- 


,> 


<y. 












or 
^ 20 












No^6 


4 










— 




_A 


^ 


















•* 

€ 
% 

Ci Zo 

Ji 10 






_S_ 


N 








• 




















No 


26 


5 










— 


A 


__ 


s. 






















S 






^ 

















HEfiJ TREPrrMENT IN CONES. 



IV. CLAYS BURNING DIRTY WHITE, CREAM WHITE, OR YELLOWISH 

WHITE. 

17. Generally Contain Calcium or Magne.sinm Carbonate or Both, and 
Seldom Reach Low Porosity. Very Short Firing R;inge. 

No. 3 (p. 218). Santa Barbara County. One mile south of Carpinteria. 
Formerly used for making light-colored common brick and building 
tile, in the Carpinteria plant of the Santa Barbara Builders' Supply Co. 
A light-yellowish sandy-shale, which develops a Aveak and sticky 
l)la.sticity, but with medium-high dry strength. The deposit contains 
lime concretions Avliich Avere sorted out as much as possible, but the 
sam])le contains too much lime for satisfactory testing, as all test pieces 
fired below cone 04 slaked in air after firing. The dry color is 17'"d, the 
Avet color is 17'"b, and the fired colors range from 9'f to 19'f, from cone 
010 toward cone 02, giA'ing a fair range of pinks and buffs. Fusion 
begins slightly above cone 02, Avithout preliminary vitrification or the 
develo]iment of steel hardness. The fired porosity is too high to permit 
the manufacture of structural Avare of good quality. The total 
maximum linear shrinkage, plastic basis, is 10.8%, at cone 02. The best 
firing range is betAveen c(mes 04 and 02. No charts of linear firing 
shrinkage or absorption are giA'en. 

Ko.41 {\^.'■l{)-l). San Diego County. Escondido. II. T. :\lorris. Thi^ 
is a poor quality of conniion-brick clay, containing too much lime for 
satisfactory use. It efferA^esces strongly in liydrocliloric acid. The 
plasticity is sufficient for brick-])ressing, tlic dry strengtli is medium, 
the drying characteristics are satisfactory, and in the dry state the 
clay is hard and coarse-grained. The colors are : dry, 19"f ; Avet, 21''''f ; 
cones 010 to 06, 15"; cones 04 and 02, 1:}"; and cone 1+, 9"i, with 



CLAY RESOURCES AND CERAMIC INDUSTRY 340 

ycllow-tjrcon blotches inflieatin<r tho presence of lime. The fired colors 
;ii-e too (lull for "rood exterior effects. Fiiifrer-iifiil iiMrdness is present 
in the dried strife, hut steel hairiness is not devehtped below the fusion 
point. Fusion coiiuneiices at cone 1-|-, without i)revi()us vitrification. 
Tlie iii;i.\inuini total linear shrinkage is (i.d'/r, at cone 1+. The best 
firing range is from cone 010 to cone 02. 

No. 46 (p. 195). 8an Bernardino County. Government Holes, 12 m. 
E. of Ciina. R. II. Ilolliman. This is a residual kaolin, too high in 
coloring compounds, fluxes and non-plastics to be of value. Tliere is 
strong effervescence in liydrochloric acid. As the deposit has been 
reported on numerous occasions, the test data are presented for those 
who may be interested. The material has fair, though short, plasticity, 
mi'dium dry strength, and is hard and close-textured in the dried state. 
The colors are : dry, yellowish grav ; wet, 17"'f ; cone 010, 13"f ; cones 08 
and 06, 13"d; cones 04 and 02,^13"b; cone 1, 13""; cones 3 and 5, 
17"". Finger-nail hardness is developed below cone 010, and steel 
hardness at cone 3. Bloating begins at cone 5, and complete loss of 
shape occurs at cone 13 (with the laboratory firing schedule used). The 
maximum total linear shrinkage, plastic basis, is 7.3%, at cone 5. 

No. 115 and 116 (p. 90). San Bernardino County. Near Rosamond. 
Merry Widow ]\Iine. These are samples of fault gouge and altered 
volcanic rock from an abandoned gold mine. Many clays of this type 
are called to the attention of the State ^Mining Bureau. The}' are 
usually worthless from the ceramic standpoint, on account of weak 
plasticity, excessive shrinkage, poor fired colors, low fusion point, short 
vitrification range, and low fired strength. Test data are presented 
for two varieties for the purpose of pointing out the defects of such 
material. No. llo is a fault gouge. It has sticky and weak plasticity, 
liigh dry strength, and in the dried condition, is hard, medium-grained 
and medium-textured. The high ratio of pore water to shrinkage water 
sliould be especially noted. The colors are: dry, nearly white; wet, 
grayish white; cone 010, 13"d; cones 08 to 04, 15"b; cones 02 to 3, 
15"i ; cone 5, 15". Finger-nail hardness is present in the dried state, 
and steel hardness appears at cone 04. The fired structure is weak, 
and wdien fired below cone 02, is granular. At cone 02 and above, the 
structure is glassy. Most of the fired test pieces have one or more large 
cracks. Vitrification is complete at cone 1, but kiln-marking begins at 
this point, and bloating begins at cone 3. The total linear shrinkage, 
plastic basis, is 24.5% at cone 1. 

No. 116 is a sample of decomposed trachyte (?). The properties are 
sinular to those of No. 115, but the shrinkage is less, and the fired 
structure is stronger. 

No. 205 (p. 229). Stanislaus County. Near Patterson. Cummings 
Ranch. This is a shale with poor plasticity and medium dry strength. 
In the dried condition it is medium hard, coarse-grained, and open- 
textured. The colors are : dry, yellowish white ; wet, 17"d ; cones 010 
to 06, 17"d; cones 04 to 3, 17"b; cone 7, 17"d. Steel hardness is not 
developed up to the firing limit studied, cone 9. The fired structure is 
moderately strong, sound, granular, and open. The surface texture is 
slightly rough. The grains composing the mass are heterogeneous in 
color. The total linear shrinkage, plastic basis, at cone 9, is 13.1%. 



350 DTVIRTOX OF MIXES AXD MIXING 

The clay would need to be mixed with more plastic material in order 
to permit its successful use in comnimi l)rick or face brick manufacture. 

No. :}6:2 (p. 159). Placer County. East of Lincoln. Valley View 
]\Iine. This is an altered irrneous rock of undetermined oritrin and 
composition. It develops <;oo(l plasticity, although a large proportion 
of the material is non-plastic. The dry strength is medium, and in the 
dried condition, it is medium hard, open-textured, and heterogeneous. 
The colors are: dry, 17"'f ; wet, 17'"b; cones 010 to 3, 15"d; cone 7, 
17"'i. The fired colors are too dull for pleasing brick colors. Steel 
hardness is developed at cone 7. The fired structure is sound, and 
medium strong, except for superficial cracks at cone 7. Fusion Avitliout 
vitrification begins above cone 7. The total linear shrinkage, ])lastic 
basis, at cone 7, is 10.7 /c. The material has doubtful ceramic value. 

TABLE No. 28. 

IV. Clays Burning Dirty White, Cream White, or Yellowish White. 

17. Generally contain calcium or magnesium carbonate or both, and seldom reach 







low 


porosity. Very 


short fi 


ring 


range. 




Soften- 


Clay 
















ing pt. 


No. 


% S.W. 


% P.W. 


% W.P. 


D.T.S. 


% 


D.V.S. 


</c D.L.S. 


in cones 


3 


13.6 


26.3 


39.9 


463 




20.8 


6.1 




41 


11.2 


18.5 


29.7 


322 




19.6 


6.2 




4G 


7.6 


10.2 


17.8 


579 




15.7 


5.1 




115 


16.5 


37.6 


54.1 


432 




20.4 


6.4 




116 


24.9 


29.1 


54.0 


550 




34.4 


10.4 




163 


43.0 


24.1 


67.1 


-1-35 




66.8 


18.4 




205 


9.4 


39.8 


49.2 


269 




11.4 


3.6 




262 


10.1 


18.2 28.3 
cent shrinkage water. 


334 




18.0 


5.7 




% 


S.V^. = Per 




% 


P.W. = Per 


cent poi 


•e water. 












% 


W.P. = Per 


cent water of plasticity 












D.T.S. = Dry 


transvei 


rse strength, pounds per 


square inch, 


without sand 




% 


D.V.S. = Dry 


ins: shrinkage, per cent 


dry voh 


imie. 








% 


D.L.S. = Calculated li 


near drying shr 


inkage, 


per cent dry 


length. 





CLAY RESOURCES AND CERAMIC INDUSTRY 



351 



2 j=. 



5 

E 



00 .— ° 






> i 



a 

o 

u 

>^ 

a 

La 

c 

o 



e 
o 
O 


-oft-' 
















CO 

o 










<; 








c5 










<• 








OS 
O 

c 


^t: 






CO I 








o '• 


i 


< 






to 1 


< 




1 1^ 1 1 


OS I 


c 


^i 






00 CO 

-*« CJ 

CO CO 






1 loco 

1 'MO 

1 -co CO 


-* Oi 
CO lO 

ci ^ 


CO 

o 


< 




'cooir- 


<MCO 

CDOC 

COCO 


<; 




.CO CO lO 


»o -* 

coco 

CI ^ 


o 


^°" 




CO t^ <M ^ 


00 CD 

coco 






c^r^ WO 

-T_J_-* CO 


COCO 


o 

s 




^N M -- CO O 


^oo 
r^ OS 

COCO 


..^ 


OSOO-^t-iO 

- 1 l^cc 


coos 

■^o 

CJ — 


c 
o 
O 




^ r^ -^ 00 r: 
lO PO M (M <M 


c» »o 

oo o 

CO-* 


> 


O O 00 Oi ^ 

r^-^ — eo w 
1 eoc-j 


CO 00 

-^o 

CJ ^ 


- 

o 


^':; 




O t^ CI CO CO cTi c; 
t^ CO r^ o c^ Ci ^ 

CC <M C^ CO CI CO '^ 






oo — CD c; r- o QO 


« C^ CJ ^ — ' oo t^ 

[ 1 eocjci — 


00 

o 

a 
o 


.=,&<■ 

^'•< 




t>- « t— OC 'T*- IM t^ 

CO CD Tf CD C^ CO IM 

CO "M CO CO CO '^ '^ 






CO' CO O: O ^ a; CO 
^ (M -^ CO (M O CD 

1 1^ 


o 
o 

c 
c 
O 


< 




t^ o ^ o »o r^ -^ 

»C CO in <M -^ "C <M 

CO CI -r -*• CO -* -rf 


'^i 




ooo « ^ ^ oo c; 


CJ Ci ^ iC C-l 00 CO 

1 I- - 


1^ 


•^ -^ — ' ^ CO o x> 
^ ^ ^ (M C^ 


Class 


No.. . 


I^ 







+ 






il 
CO 

65 



352 



DIVISION OF MINES AND MINING 



Absorption and linear shrinkage curves for clays of class 17. 

. 010 08 0b m OZ I 3 S 7 9 II 15 IS" 

*o 

^ 20 

% 

Ci 10 
Uj- 

'^ 30 
^ 20 

♦« /o 

IS 

^ 

f:; 20 

I 
?, 10 

/Vf/!7 TREATnfNT IN C0NE5. 





A 






^ 


No 


41 














































S 
























A 








No 


46 






















S 








^ 


^ 












V 










No 


II 


5 










N 


sA 
























s 


— 


< 






\ 












y 


"s 




\ 


■*^ 
















\ 


< 








No 


1 1 


6 












s 




Si 


"C" 


--- 


... 












^^ 


"5 






s 


\ 


-^ 













i2 
ft: 

-J 



OIC 08 Ob Of 02 I 3 S 7 9 II 13 IST 



30 
20 
10 

30 
20 
10 










r 


No 


16 


3 




— I 






A 
























\ 






















_s. 


,'' 






















s 


s 


A 






Nc 


20 


5 


















^ 






^ 


— 












s 




















... 


,'' 




" 



















30 












No 


26 


2 












A_ 




_ 
















20 

10 

/■I 




















"~* 










.. 


-- 


_S 


— 


— 


-- 


— 


-- 











//£A T TREATnFN T IN CONES. 



cJjAY resources and ceramic industry 353 

chemical analyses. 

Table No. ;!() <;ivcs cliomieal analyses of ('crtaiii clays from (li'i)osits 
that were sampled and tested. About one-half of the analyses were 
made on a portion of the same samples that were tested for ceramic 
l)roperties and therefore can be directly correlated with the results of 
the tests. Tlie other lialf of llu' analyses were compiled from the litera- 
ture and from data presented by certain of the clay manufacturers. 
The sami)le nund)ers to which these analyses correspond are given in 
parentheses, but owino; to variations in the character of the clay being 
mined at ditl'ercnt times, the anal^'ses of the samples actually tested 
may be considerably different from those given in the table. 

Table No. 31 presents a group of chemical analj'ses of deposits that 
were not sampled. Very few of these clays have possible uses in ceramic 
manufacture, except for common brick. The analyses are given as 
being of possible interest in the future and to serve as a guide to the 
character of material to be found in the localities noted. 



2:^ — .-,^07!> 



354 



DIVISION OF MINES AND MINING 



o 
a. 

Ui 

D 
a 

UJ 

_i 

< 
V) 

o 
oc 
u. 

i/i 

>■ 
< 



C/5 
UJ 
</J 

>■ 
-I 
<t 

z 
< 

< 



UJ 

X 

o 



on 

< 







r^r^ 




IM C-1 






1 ^H03 i-H 










OO 




eo 






U3 lO 








OO mn 


1 OOJO 


C& 






g§ 






c^(M ccec 


1 (M-^IM 






CM 






do. d d 


d d d 


d 




d 


dd 






X><' KK 


^"xx 


x" 




X 


x"x" 






rersity 
R. XI 
R. XI 

ersity 
er.<ity 

ersity 

ersitv 

R.XX 

R. XX 

ersity 

ersity 

•ersity 


XXX i-i' 


^ 


£■ 1 X i- i? £•£? 


XX i- 




.t:;* 


M.R, 
M.R, 
M.R, 

nivers 
nivers 

169 


169 
nivers 
M.R. 
1173 




««'? 




.£3 


Stanford Uni' 

& Co., S. M. 

& Co., S. M. 
Stanford U iv 
Stanford Univ 
Bean & Co. 
Stanford Univ 
Stanford Univ 

& Co., S. M. 

& Co.,S. M. 
Starford Univ 
Stanford Univ 
Stanford Univ 




• • > OO 

SS-5 2 




3 

O 
Vi 


Co., S. 
Co., S. 
Co., S. 
nford U 
nford U 
.\ngeles 

. s. e. 1 


&Cn. 

. C. S. 6. 1 
Stanford U 
& Co., S. 
. C. S., 6. 1 


Stanford U 

& Co.,S. 
1. Co. 

Stanford U 
. C. S. 6. 1 
Stanford U 

Stanford U 
Stanford U 


Co., S. 
Co.,S. 
nford U: 
n&Co. 
. S. S, 1 




>. 


ery & 
ery & 
ery & 

er, Sta 
er, Sta 
.s, Los 
I. A. C 


mery & 
mery & 

mer, Stai 
, McBea 
, .1. A. C, 




c 


W. Briggs, 
lith, Emery 
lith, Emery 
W. Briggs. 
J. Minner, 
idding, Mel 
W. Briags, 
W. Briggs, 
ith, Emery 
ith, Emery 
VV. Briggs, 
W. Briggs, 
W. Briggs. 


o ^ (at o K_; 


Minner, 

h, Emery 
Clav Proi 

Minner, 
hfiel, .1. A 

Minner, 

. Briggs, 
'. Briggs, 






1 B s a = s s ■- 


e~.5fe~ 








h.E 
hficI 
■Br 
h,E 
hfiel 


h. El 
h.Ei 
Mil 
ding 
hfiel. 






.^.-^.^^^u, a 


1 t:; L !? "tiJ t; 




: 1 ^ ^^£;^ ^is 


.■^.ti~-^ £ 








s a a,^- ■„• 3 


S3 .'a =! 




a a •- 3 






a2Maj>>!i3m 


c/:' CQ O t/j CQ 


U* 


1 cA' cu > 03 > a o 


cococpa 






oaiooor--oooo;ioooo 


— • o OS :o -^ o o 


O <M O 00 CO 


CO — - oi -f »o c-1 ac o 


iO — ' 00 CM 05 




5,>- 


O^O; 0050000COOOO 


IM O CC (M OS O O 


kO — O Ol C) 


CO OQOiOOOOV "O 


oc O CO oc o 




oL 


OOOOOOOOOOi ooo 


o o o o o o o 


O O O CR O 


1 _ 


1 O 05 r!i CTi C!!5 <!:^ f!5 


oc o o o o 




E- 


O'OOiOOOOOOOiOOO 


o o o o o o o 


ooooio loocr-ooo oo 


ooooo 


!■? 


iOfM-MOOOCOCOOsr^cO — tOlM 


rf I^ -^OOO ^ 


00 CO t^ CO CO 


•* CO CM lO CM O -^ 


— O CM UDOO 




— ^ 


'^C^iO'^^t^COh-COcCOOCO*^ 


CO t^ iM ^ « O 


dC^IOS CO Oi 


CO ^- CO ^- t^ OO CO 


— O CO CM O 




.B's 


CO ^ :o 00 '-o r- o; ^ -H -M -^ -rj O 


— QO ^ O O 00 


00<MCOOO 


CO 1 CM OCOiO CM OO 


c: o r^ cr. o 




1—4 O 


^« "" 


" 






l^^^„^ ^ 







H 


o 


s ^ 






CO Ci 
OCM 






c 


o 






°9 




^ CO 


o 


O CO 




1 o 






O.o 


CO in 


Oi 


OO -^ 




1 lO 






P'" 


OO 


o 


o — 




^ 




o 


^ ^ 


»re lo 


lO 


c^ 


CM lO CO 


t^r^oo 


.5 

9 


lO a; 


I-- :o 


OO 


oc 


t^ CM O 


O US'* 


«.. 


o o 


o — ■ 


o 




d o! ^ 


dod 


0.1 


OS CO ^ en »o cor>-(N 


u:if^ o 05-* 


CO CD CO Oi 




iJCO "ti CM 


I^CM 


£ 




T-i o CO cor-- >— " 00 Tf 
^c^j.-o^ oo ^oo 


O O C5 -^ ^ ^ O 


00O5 — o 
CI O O o o 


't 


^- CO 


C^l 


lO — 




O '^ o a: cc 


M- — t^ o — 


3 


O.o 


^ . - . ^ ... .... 


" " " — r~ " " 


Cv| -■ w . . 


oc 


" rt- « o — =• 


*o-* — " ** 


'i 


w'^^ 


o 


o — 


o 


c^ 


ooo 


odd 


o 


M*»00 .•;0'*:f .• .■ic»oco»— «o 


O (U . • CO ■^ -^ l" 


X t-' fc-' t-" J2 


r^ 


L," ■^ ij tJ ^o o oo 


— — o .• — 

»0 CO lO i CO 


1 


OiCC^^i— CO^ci^OOOC^lO 


IT 


s"^ 


ooo OO ooe>oo 


o a ooo 


o o 


c 


o ooo 


ooo d 




CO OO Oi -^ ^ — ' -ff Cr- »0 <M — CO O 


CO t^ cc C-J :0 O CM 


0.50 
Tr. 
0.16 
0.68 
0.72 


^ 


0.39 
1 90 
0.10 
Tr. 
21 

0.36 
0.92 


■«i" CO cr. OO CM 




g^ 


i-i-^OO--*''— C^CDCOOCOOCO<M 
OOOOOOOOOOOOO 


C>1 I^ o »o O 00 -* 
OO O — — O O 


C^ 

c 


Cfi CO O CO iC 

o — o o o 




« 


00-f-f^G0C000iMO5t--ir:»OO 1 


-* C-. ^ O 00 , • CO 


<M CM CO Ol — 


oc 


1 00 CO -^ o ^ coco 


1 O iCOO CM CM 




Q-o 


osr-'f-fcoc^". O'— lO"— 'CO-— 'Oi 


C^l (M C^l O »0 r^ CO 


CO (^ (M o: lO 


iC 


■O O t^OO Ol CO — « 


r^ cr. 00 i^ lo 




£"■ 




<M -H (M — O CM 


O O r-i O O 




CM CM CO O ^ COCM 


CM COCM CM CM 






oiOiooeo'Mr^ooococn'^co'rt" 


OO t^ CM OO »0 CO OO 


O CO 00 CO •— ' 




c; CM ^ OOO CM CO 


lO CO COCM OO 




q,.o 


oso^ CI— eoc^i CM oo—'i^co-Hno 


CM O C^l 00 OO CM 00 


O -^ -* iCM 




»C CC CO lOOO IDOO 


t— CO CO CM '^ 






COiO*— '^HOOOi cOf--'— <0»OCO(M 


CO -I' CO r^ icio CM 


CO CO(N TJH (M 


t^ 


Oc r^ r^ .— « CO CO ^^ 


-* cc O c^ t- 




<'^ 


C^COCOCOi— '.-<(MC^CO(N(MCOCO 


C^l CM ^ ^ CM CM CM 


W '.** ■<»< CO -s* 


cs 


CO CMCO ■'1' CO -^ -^ 


CM CM CM CM CM 




Oioot*'— '•O'Mooiooior^coM 


■^ CO CO CO Cv» O O 


OO »or^ — CM 


w 


1 1 O 00 00 00 — »C CM 


O 03 cr. OO CO 




i^ 


— — — 'C^OO<M — "CI — COOi-rJH 


.^ CO -*- t^ »0 O I^ 


r-^ OO — • 00 r^ 


cs 


1 1 CO CO O Tf if^ CO 00 


00 UO iC "* o 




COOOOiOlCO — OOCDOO-^CO-^ 


O CO to ^CO -r CO 


o -rf CM 00 r- 

CO IC "^ -^ CO 




ll^r^i/?.— 00 OCO 
llM'iOTrM'-^ COiD 


O iC 00 -rf OO 




CO 


co-rf-^iOf^t^^coiCirjcCTfiO 


»0 CO t^ I^ CO CO t^ 


cc 


CO lO CO CO *o 






I 1 ' ' 1 


, 1 




, ci . : ; 1 




a! 


o 




H 
















t-> ! . 1 








c: 






. , a>io 


c: 


'oT'^ 


























o 


1 1 




1 ' C . 




3 3 


; s 




o 


, E-102? 
;o Co. . - 


d 

O 
a; 

c 


a Co.... 
aolin 

(med.). 

(soft).. 

0. 




-a 


. Co. Scl. M 
Co. S. H.-3 
. Co. M. T. 
.Mfg. Co.. 




H 

s 






1 1 
COM 




, Bone. 

ay 

0. 26 bo 
iloan No 


'a 

3 

.a 
bO 


CD 
bC 

c: 

2 
o 


2^ 




CI. 

Q 


o o 57^ £ 


Nevad; 

eked k; 
No. 2 
No. 3 

eras C 

a _ _ _ 


2 

o 




d 


i 


Q- rt 6 6 




o-Z"J 


s 




6 o" 

OO 


id 




o 


^^ s § & 


H 


^d^i 




o 






d*^" . 


d 




=B"8 5 am 




jj ^j TO t- W 


.yaggjiw 


»<i^=aM 








•a-Sm«|pQ 




o 


Alberhill: A. C. 
Alberhill: A. C. 
El Cajon Mtn.. 
O'Neill Ranch, 
Hunter Ranch ( 
lone sand (type 
Pine Hill Kaoli. 
Clark & Narsh, 
Weiss, Glen Ell 
Weiss, Glen EU( 
Nigger Hill, Cal 
Ryan Ranch, T. 
Amer. Ref. Co., 


11: A.C 
II: A. C. 
11: A. C. 

t. Stand 
t. Coors 
t. Coors 
11 (G. M. 


is^dd 




^:^<^, t< 










hill: El 
hill:G. 
Jones 
hill: A. 
hiU: A, 


a. 


1 ^^j_:^c^ 




11, A. 
11. A. 
, Wir 
. Wir 
I1:G. 






:£:h:h22S3 


o 


'js 2:s:3^:e g~ 


3:Stein:5 






9^ a> o t^ ■J-' t^ a> 


L. t- .. Lh h- 

O) O CJ OJ QJ 


<1 


j£|lil.B| 


fefc^^ fe 






£^^ i^ rt rt-^ 


.aj= aXiSi 


c: 








<<-<ffiEa::-< 


<<^<< 


c 


<Ci<<^< o 


Clav 




— <c^r^c-iirooooO'^»ooo?5 
■^ _ „ rt „ _C»,C.] ^^ 


^-~--^^-v ^— ..— ^ 


^^^ ^_^,,^ 




, _,__ 


^^ ^.,^^ 


San 
No. 




»C OO cr- -^ r- i-^ O 


ooo o coco 


>c 


(^ t-, to ^ — — CM 


OS COCOCM 


iple 


— (M <M Tj- lO "^ oa 


r- Oi CM r^ r* 


c< 


— CO oo O M- CO 00 


^ — ' CO CO 02 






^— '-— '— CM CM 




•—"-^ — „ (M CM 




I 


^ — 1 












Clav 




1 


CM 1 


1 


■* 


« 


CO 


Cla 


's No.. 










1 






1 






1 








1 







CI. AY RESOURfES AXn PER AM IP rXDT'STRV 



l^f);") 















II 






g 


II 


1 






'§ 




1 










1 




Cfl 






CM 
















d 








d 




>, 




>. 


>. 


>.>, 




x' 








X 


!>■, 


*x 


>. 


•^ i-.^ 


•gi- 


i' ■»;■» 




><.^ 




1 >, 




Xi? 


'^ 


fc« 




■1 1.1 


fc- ■-* 


k- h. 














k> 


> 




>t 


jl.ll 




oig 








«l 




'H 


> 


\ y = > 










> "2 


1^1 


== 


^ 




^ '=^ 


^ Uj-= 


'■•^Ui 




Sn 




•= 2 


L- 


.*« 


:_> 


T3 :^^ 


'— — t^' 


•^.^ 


d 


"^-? 




t-i 


- 


l-o 


i 


■-, 


^ •S'2 


«,- §-^ 


- t 


O 




~0 5C-' 


' c 






Vh U- 


^ ^ 


1 


• fca 




k. 






1 **•* 


1 

CO . 


3 


CO 3S 


d^ 1^ 3 


5 rt 


o.o 


d 

a 


•2d «i d 
2" d ti 




i B 

: CO 


jT 




_- ojco 


<-B' -st- 


-c'^' 

o C- 


pa 


"S 


"i-s -<• •? 


|Ih..h 

1 .^ e9 OS 3 


'C 


.2 


.Si to to 


-'^i -£11 


'■£■£ 


-1 


1^' 


(i; 






^ 


k. 


.2 -E-C 


_- >. c3 .H-n a 


' C Sj 


OC C3 


>. 


c >» - 


-- >i 


b 


n 


Q con 


;g.2PQ Qaam 


:a5 


= P3 


C3 


So 1 o 


QCQpa<; 


^ 


- 


b- ' ' - -^ 


fflaJui isd^ 


■sis' 


7^ i^ 


Jd 


<£ 


.03 3 «S 


co> 


^'uiuiJ 


t* 


§ 


r* — olc^ooo otoo 


■^ — 


CO O CMO 


-•. 


! d OS •*" ?o 


1 Oh- 


1 Oi O o O 


o 


00 coo 1 »0 -H O iC o o 


1 S-. ^ 


=i O OO 


ec 


1 h* ■«!f CO OO 


O 05 


1 OSO o o 


o 


o 


OO OO'ioscsO CICC: 


o o 


C: O 1 d O 


1 2 


' O Ci CS OS 


o d 


d OO o 


c 


o 


35 OO'CiClO ClOO 


OO 


— . O 1 O O 




loo O CS 


0-. 


OiO OO 


^" 


^^ 


^" '"' t ^" — ^- 


"" "" 


— 1 1 ^ *~* 


^^ 


1 1— 1 .-. - 


■* 






CO 


C-. 


O COlO 


1 o a> ■* CO c-i 


OCO 


S: CI 


U50 


?o 


CCOO CO -^ 


030 


t^c<o « 


00 


1^ 


t^ OO 


1 C5 Cl »r3 o ^ 


; CO O 


CI =s 


lOCM 


•^ 


-*** CI o -** 


0-* 


Tfosec-" 


at 


OO 


d 00— ' 


o CO d C-. o 


od 


.^Cl 


00 U3 


lO 


cod d 00 


•^Vi 


^ri ^ ^ iC 






-,,--- 














I-H 


•-^ ^- •— 1 ^^ 






^ 

d 


^ 






^ 














OO 


o 








r- 














CO 


«-M 








C» 














d 


!-• 








d 




CM 




O OO 


O U5 


ts a 








CO 




ex 


CO 


I^ 




CM CO 


CO -^ 


lOTf 








'«*' 




00 


eo 


O 




o o 


do 


OO 








d 




d 


o 




C-1 


s 


c mo OO 




00 


OC4 


Tj< 


C5 (M CO 


o 


^la^ 




o 


.^r r^ — t^ 












od -^ d 


CMO 


OS C< M 

uTdi-^d 


o 


"^ 


^ 2o 


•~ad -.c OO d 


00 o 




CI 


" 


" " " — "* " 


^d 


^ 1 


M e« 


M 


CS| « ei 


e» 


" CM 


CM « « « 


c 




3 c 


do 


dd 








d 




d 


d 


„ 


c^ 


C5 OO . 


O O UO CI CT'l' 


t COCO 


l^u, 1 


^^ 1 


00 


■«?< CO CO »o 


iJ ^' 


CS-f CO — 


00 


o 




CM CO -^ ifi « « 


o>co 


o- 




lOO 

e<id 


CO 

d 


CO ^^ CO o 

dd d d 


O-^ •-•CI 


=5 


odd d d — 


dd 


^ f- 


OO 


in 


o -fOoi'OTj-oo ^:r::o 


O lO 


W5 lO t 00 :0 


w 


C4 O O O 


0) ^ 


^^r^io OS 


Ol 




Ci iCO'lCS'**^ OiD»0 


ooo 


— T -^ ^^ 


TT 


^— O OS 


15 


CSC0-(J«O 


^^ 


d 


o CO ' ooo ^do 


'=>C> 


— d 


— lO 


d 


-^o c^ o 


OO OCl 


_ 


CO 


»o -^ CO t^ O cr. -rj. --c <M 


coo 


C; CI 1 O CM 


o 


■^ t^ -J 


O 1 


tflr^ 


ClOO — OO 


■^ 


m 


-r <—r— ,1^ — 00 -*oo' 


«->• 


0-. O 1 CO 00 


<M 


iCM O OO 


t^CI 


t>-i^ coco 


CI 


-* 


(M (M -^ M — ' (M (M C^ !M rr 


CMci 


CI -* O^H 


"* 


t^OO lO »o 


h-t-^ 


eooics — 






1 




*-* 












C5 


CO 


Ci coc'ic--ro« csc^ioo' 


mo 


— O |l 05 


00 


OS— M OO 


OS CO 


d -* r^ ci 


00 


C>) 


(TO ^C«i|t^OOCi CIClCO 


^lO 


— 1.0 |l coc» 


•r 


r^oo CI o 


— ^ 


ooo d CO 


OO 


C5 


(M — (N 


00 05 lO O 00 CI 1 


CO CO 


CI -^ 1 [ CD CM j 


OO 


t^ -^ OS — 


lor^ 


deoooci 


T-J 


CI 


CO ccco 


CM CMCO CO CMCM . 


CO CO 


CO CI ■! — CM 




— c^ .- 


CM 


— CO 


C) CI — c» 










II 1 






1 






»c 


to 


CJ 00 00 


!D!Ot~ OOO 


CR»0 


ooc^ Hot* 


o 


-*t«oo w o 1 


t^^^ 


O-^CDiO 
00 CO lO CO 


'-^ 


CO 


1- M ^ 


iO t^ C5 COCO O 


-^00 


COt^ I <MW5 


CM 


OOlO »- 


- 


U30 


u^ 


»c 


'M t^-^ ;l ifD — Ci >f5 CO ^ 


<M <M 


O ifS 1 oooo 


d 


CO (» C^ CO 1 


00 d 


CO 1— 1^ (O 


»r: 


iC 


1 


UZ tfi tfi ut »C O 


»C i^ 


II 


t^ 


cOiC cc 


o 1 


o-«. 


^tmn'T 


lO OO 


»o 


00 : . 1 


■ ' •« 'T^ ■ 


■ < C3 


: , II oJ <j 


% 




D. 




3 ; 


', \ ', . 


C-J 




■ C3 




03 I > 


CO Isd is.;; 

dQS^ '2 b 


; ;- 

; ;2 

o :s 

d d . 
d d^ 




2 J 


-5) 

i 

Q 

1 

d 




2 
1 

d 

O 




o • 


1 1 : 

■ t < 




o 

c 
Z 

o" 


o 
d 

d 


• d 

:z 

I d 




2 id 
. :o 

& is 

a is 


> 03 


II fe^ 

ii";^© 

IcS" 

d-« 


•3| 


■a 

09 

'S 
6 


a ; 
•S.S 

0-3 


1 ' ^ 

00^ 'v 




o; 


&; 


;CU 




PM ;s 


«■&; &&; ij^s 


ddS 


;ii-«l 


fc 




CU 


m3 


p^^^a 


d 


d 


|d 




d ;ii 


^"•■^d idf 




d 




d 


^1 


. CC CD ^ 


.. a 


,j 




CJ 


-; ' » 

cj:— 




Jj'd 


a! 


ft-' 


.1: s 


..5.S a 


coin: 

coin: 




^i-^-r: r:c;-ii5^C^ 


-f-f-i 


^.ii'il' 


fe 




> ? 

o 


— o 


v;ccco g . 

g o o o 


— m C 


M C 






"S II-- 




«3=2~ 


-O 


-^ C 1! 


.s-s-sj 












^^1! 


12 J 


■^ 


jIj i-j 


K |! <->: 


<: 


oa<: 


-H- 


j>>s: 


^^ 




__^ ^____, ^^ ^ ^_^ 





|| ^,^^_^ ll 


^.^ 


.— v.— . 


>— S-— . 


^_^ 




"5 lO 


o 


O CO,i— OCCCi Ci-^: 


o r^ r^ 


ci,|^-l 




lOO o 


CI CO 


t^CM 


OOCl CO o 


TT -^ 


»o 


lO izO'O^ffO'Tl- 't^O' 


-r -f>.o 




CO-* O 




^CM 


-*oo — 
















" II 


-* CI CI CI 






"— ' II •-^•— '^-^ -— ' 


■— ' 


^•^ 


■-^ 


•^-^-—' 








ll 1^ 


00 


:'=» It 


o 1 


c»» 


1 


n II 


•^ 










11 








II 


II 


— II 






1 


" II 




1 



a 

E 



a. 
S 



B 
O 

Qi CU 

^S 

o o 

= a 

2 o 

GO a 



a o 

C.B 



en C 

Gi B 



C I. 









V s.^ 








S a S 






o 


STte 






o 

II 


^"c.^ 






S E >. 






O 


E 3 J . 








a X „ tfi 

"^ c-=S 

i E g 3 






^6 


*^ X r^—* 


CI 

o 




d2 

II cS 


fc --^ s 


o 




^gE^i 




C 

CO 


ft.5 



356 



DIVISION OF MINES AND MINING 



a 




111 


a 


^ 


J2 


Q. 


9 


S 




< 




CO 


^ 




3 


1- 




o 
z 


s 


(n 


X 


> 


P 


< 




-1 


C3 


o 


C 
03 


< 


"3 


z 




c 


d 


o 


f:i 


u. 


o 


_l 




< 




o 




at 




3 




O 




liJ 





111 
u 

CO 



a> 
111 

CO 

>■ 

< 
Z 
< 

_l 
< 

i 
111 

z 
o 






as 

^ ^ t:^" ^ -< l^d h^ t^' ^' iii i^ >:d ^" Ui ni t^ ^* t^n' t4 ^ iii t:d t 






o o 



>< 
X 



c =: a c c c: c 



*- ^ C* i, ' 



; :^ *^ ^ ui iii lii ui tii ui t:d tij ui ui t4 



^ -J _• __• CC (Tl lO 

X - s s »c 00 r^ 
=3 :3 3 3 cj -c ro 



■^^-t~*'?':CfMn— -icio-^ooo- ^ Soo 



O 



i;'H'x"5*^ — "S i;"S"2 — "5"2'^"5 — "9 =; ^ — "H — x^"^^^^-"x'^oo'x'^'x"^ 



c-c-c-^-^-3- 



3 -^ C-1 C-l O i.*^ CC CO t* — C^l <-« 



303 3^ P^OOOO — ^C^C^'^C^— 3 " 



; iC O r. OC OC C^J 






l>- CC 3 lO — -?■ — 






cc oo :^ o c^ M r^ 4f: -^ 00 -^ •* t-- c» t~ r-- — t-- t^ 



;-ri^>f; — c-i'^»ct^c:cr. oow-^occcac*--:; 





o 


o 




Z 


a 






bl 




-1 


S 


CD 


a 


< 





-Cede 

o o o o o c: c 
>>>.>>>. >.o o 

c c c c c ^ >> 
eS C3 cS ed c3 e c 

^ ^ . . . wO 



^^^^ZSS:5S 



O 






-u--=: c c3 









ZZt. 



L. L. L- L. 



af^X. 



« ; 



z. 



a. '^ "" 



X -r, X "-- ~'-:::*3 ^' 



" ^-^ C C-i s ^' 



^lifc^i. 



i-«';"5t-- t-t: =c 






£«ffli2i5i55a2SK'S2S 



g > > 



w OS 09 

9 9 9 



S ^ ij s_ o w> cj ;z; ^ ~^ ti u t^ 

— t- t- C S- t- t- — — ^ t. t- — 



SSScocc — ■ 



:^^ Jcc 



wC^w — SS2^ 



:s;z 



t: = -i5 



5 '^ 



-#= = 63 



S-^ 









=- i -Is 



w _^<; 



2S: 






; rt ci :i «^ 

: rx 31 £- Ch ;z; 



q 






E x X X X a: 

5 r5 



O O O 0-0'^'T3'Ct3'Ct3"3 "3'C ■— -— -^ ■— 5 5 , , •' " ■"■": -^ _3 . " T , "^ . " 

C C C C CJ o cj CJ Ci o ii c Cj C- ^ J J^ f .— — — X X X X X X X I. X X 

— — ._ — , aocjoowtJuocjrT-r r ■"; ""= 3 -—■—•—■—■—•—•—•—•— ■— 

— «- — >-t-i-fc,fc-t-t-t-(-»-i- — — — — „_, — — ■- — — — — — — •- — 



- a c 
^^ S 

X X ^ 



6? 



O 



CLAY RESOURCES AND CERAMIC INDUSTRY 



357 













INDEX OF CLAY SAMPLE NUMBERS 














^§1 




4 




CO r* 

?g- 




?«-! 

m 


■ to 


1 ^ 




■a at 

•a a. 


253 


13 


•Si 

»g- 






: f^- 


; F 




; '5.'"^ 


: f 




• 5^ 


; F 




; H.'"^ 


; S 




; v-^ 


; -^ 






\ f 






1 5" 

, _3 


* 




i 1 






1 f 






i f 




1 


218 


338 


59 




265 


111 


176 


315 


162 


159 




223 


141 


343 


2 


218 


338 


60 


" ioo" 


340 


112 


178 


324 


163 


159 


"m 


229 


175 


300 


3 


218 


348 


61 


102 


341 


113 


178 


324 


164 


150 




230 


175 


300 


4 


234 


338 


62 


145 


259 


114 


90 


312 


165 


159 




231 


175 


281 


5 


234 


339 


63 


140 


260 


115 


90 


349 


166 


138 


"316" 


232 


175 


281 


6 


234 


339 


64 


140 


260 


116 


90 


349 


167 


138 


315 


233 


70 




7 


169 


328 


65 


141 


322 


117 


131 


324 


168 


136 


313 


234 


70 




8 


169 


3^1 


66 


179 


277 


118 


192 


341 


169 


138 


313 


235 


70 


"""263 


9 


169 


287 


67 


179 


277 


119 


74 


325 


170 


136 


315 


236 


68 


263 


10 


169 


334 


69 


169 


323 


120 


53 


272 


171 


136 


329 


237 


68 


263 


11 


169 


257 


70 


169 


272 


121 


53 


302 


172 


136 


342 


238 


70 


316 


12 


169 


257 


71 


169 


278 


122 


53 


328 


173 


235 


313 


239 


52 


281 


13 


169 


296 


72 


169 


328 


123 


56 


335 


175 


65 


304 


240 


52 


274 


14 


169 


287 


73 


169 


323 


124 


56 


302 


176 


66 


325 


243 


52 




15 


169 


264 


74 


175 


278 


125 


53 


273 


177 


66 


336 


244 


52 


"281 


16 


169 


314 


75 


175 


335 


126 


52 


279 


178 


65 


325 


245 


52 


300 


17 


169 


277 


76 


175 


288 ; 


127 


57 


335 


180 


77 


326 


246 


52 


300 


18 


169 


321 


77 


175 


278 


128 


54 


261 


181 


80 


336 


247 


52 


300 


19 


169 


311 


78 


175 


288 


129 


62 


261 


182 


81 


326 


248 


52 


301 


21 


169 


334 


79 


175 


278 


130 


62 


290 


183 


81 


326 


249 


52 


301 


22 


169 


335 


80 


175 


297 


131 


62 


329 


184 


80 


342 


250 


52 


282 


23 


169 


277 


81 


175 


289 


133 


63 


298 


185 


80 


342 


251 


52 


327 


24 


169 


321 


82 


175 


315 


134 


58 


261 


188 


92 


336 


252 


52 


305 


25 


169 


311 


83 


175 


297 


135 


58 


312 


190 


133 


261 


253 


52 


301 


26 


169 


321 


84 


175 


289 


136 


58 


302 


191 


133 


280 


254 


52 


301 


27 


169 


287 


85 


175 


298 


137 


57 


266 


192 


133 


281 


255 


52 


313 


28 


169 


264 


86 


175 


279 


138 


57 


280 


194 


227 


262 


256 


52 


330 


29 


169 


264 


87 


175 


279 


139 


57 


290 


195 


227 


262 


257 


52 


291 


30 


203 


339 


88 




315 


140 


56 


280 


197 


227 


291 


258 


52 


292 


31 


204 


340 


89 




341 


141 


58 


280 


198 


125 


329 


259 


45 


263 


32 


205 


322 


90 


"173" 


265 


142 


58 


280 


199 


74 


326 


261 


159 


328 


33 


205 


287 


91 


173 


260 


143 


185 


274 


200 


73 


342 


262 


159 


350 


34 


205 


288 


92 


173 


289 


144 


185 


273 


201 


69 


305 


263 


159 


292 


35 


202 


322 


93 


173 


265 


145 


156 


291 


202 


68 


337 


264 


42 


343 


36 


201 


311 


94 


173 


311 


146 


156 


303 


203 


68 


337 


265 


40 


343 


37 


201 


259 


95 


173 


311 


147 


156 


303 


204 


68 


299 


266 


140 


292 


38 


201 


259 


96 


173 


272 


148 


156 


336 


205 


229 


349 


268 


140 


260 


39 


203 


296 


97 


173 


290 


149 


156 


298 


206 


232 


327 


269 




316 


40 


203 


322 


98 


173 


272 


150 


156 


291 


208 


57 


262 


270 


"140" 


282 


41 


202 


348 


99 


173 


312 


151 


156 


303 


209 


59 


263 


271 


169 


301 


42 


181 


340 


100 


173 


323 


152 


147 


304 


210 


186 


337 


272 


169 


292 


43 


181 


340 


101 


173 


298 


153 


147 


299 


211 


81 


342 


273 


169 


273 


44 


196 


264 


102 


173 


290 


155 


151 


325 


212 


186 


337 


274 


169 


302 


45 


196 


264 


103 


173 


260 


156 


151 


299 


213 


59 


299 


280 


147 


305 


46 


195 


349 


104 


173 


279 


157 


151 


304 


214 


131 


327 


282 


141 


282 


53 


195 


288 


105 


173 


324 


158 


138 




216 


213 


327 


283a 


232 


314 


55 


195 


314 


108 


176 


290 


159 


137 


"261 


217 


213 


327 


283b 


232 


314 


56 




297 


109 


176 


266 


160 


137 


261 


218 


181 


329 


284 


232 


316 


57 


"194" 


264 


110 


176 


298 


161 


159 




221 


141 


330 


285 


232 


282 



358 



DIVISION OF IMINES AND MINING 
INDEX TO CLAY SAMPLES, BY COUNTIES 



County 


Name of property 


Designation of clay 


CO 
» 

B 
•a. 

p 


03 

p 


Description of 
property, 
page 


-9 




W. S. Dickey CM. Co 

M & S Tile Co. 


Niles __ 


265 
264 
259 


15 
15 

1 


40 
42 
45 


343 




Niles 

Tesla 


343 






263 












Arroyo Seco Grant 

• 


Baker 


126 
125 
120 
122 
121 
240 
245 
247 
246 
248 
249 
250 
251 
252 
253 
254 
255 
239 
256 
258 
257 
244 
243 
128 
124 
123 


5 

4 
3 

13 
8 
4 
7 
7 
7 
7 
7 
5 

12 
8 
7 
7 
9 
5 

13 
6 
6 
5 

8 
14 


52 
53 
53 
53 
53 
52 
52 
52 
52 
52 
52 
52 
52 
52 
52 
52 
52 
52 
52 
52 
52 
52 
52 
54 
56 
56 


279 




Gage 


273 




Jones Butte fireclay 

Jones Butte laterite 


272 
328 




.Tones Butte 'unctuous'.. 

Lot 237 E. side 


302 
274 




Hole 55-1 


300 




55-2 


300 




55-3... 


300 




56-1 


.301 




56-2 


.301 




56-3 


282 




57-1 


327 




57-2 

57-3 . . 


305 
301 




57-4... -. 


.301 




57-5_ 

Lot 254, N. E. cor 


313 
281 




Lot 255, Hole 60 

61 


330 
291 




62 

Lot 324. Hole 54 

Lot 336, Hole 47 


292 
281 




Shepard sand 


261 




Yaru No. 1... 

Yarn No. 2 


302 
335 










Bacon and Bacon 


Bacon blue.. 


139 
138 
127 
137 


6 

5 

14 

2 


57 
57 
57 
57 


290 




Bacon bottom .. _ 


280 




Bacon red 


335 




Chocolate 


266 




Carlile 

N. Clark & Sons 


Carlile sand 


208 
134 
136 
135 
213 
209 
141 
142 
140 
130 
131 
129 
133 


1 
1 
8 
9 
7 
1 
5 
5 
5 
6 
13 
62 
7 


57 
58 
58 
58 
59 
59 
58 
58 
60 
61 
61 
61 
63 


262 




Clark sand . 


261 




Eckland 

Fancher (W. S. Dickey C. M. Co.) 

lone Fire Brick Co 

Newman Estate 

Yosemite Portland Cement Co.. 


Dosch 

Doschstripping 


302 
312 




Mottled 


299 




Sand 


263 




Fancher yellow 


280 




Fancher )lue 


280 




Sand 


280 




Carbonaceous sand .. 


290 




Pink mottled 


329 




Sand .- 

Harvey 


261 
298 


Butte 


Lund Ranch 


Common. 

Common 


178-1 
-2 
-3 

177 
176 
175 


12 
12 
12 
14 

12 

8 


65 
65 
65 
66 
66 
66 


325 




Oroville-Quincy Road.- 

Table Mt. C. P. Co. 


325 
325 
336 




Decomp. igneous. 

Yellow plastic... . . .- . . 


325 
304 










Calaveras 


California Pottery Co. 


Nigger Hillkaolin' 

Nigger Hill'kaolin' 

Valley Spgs. blue 

Valley Spgs. pink-mottled 

Valley Spgs. yellow 

Helisma.- 


236 
237 
204 
202 
203 
201 
238 
233 
234 
235 


1 

1 

7 

14 

14 

8 

10 


68 
68 
68 
68 
68 
69 
70 
70 
70 
70 


263 




Helisma 

Penn. Min. Co 

Texas Min. Co.. 


263 
299 
337 
337 
305 




Kaolinized schist 


316 




Kaolinized schist.. 






Kaolinized schist.. 






Kaolinized schist. 


263 


Contra Costa 


N. Clark & Sons 


Walnut Cr. shale 

Shale . . 


200 
199 
119 


15 
12 
12 


73 
73 
74 


342 




Port Costa Brick Co. 


326 




RichmonH P. R. Cn 


Shale 


325 










Del Norte .. . 


Musick 


Common 


180 


12 


77 


326 








Humboldt 


Angpl R.anp,h 


Pottery (red)... 

Common 

Common 

Common _ 

Common 


181 
185 
211 
183 
182 


14 
15 
15 
12 
12 


80 
80 
81 
81 
81 


336 




Loof bourrow 

Strong's Station 

Sunny .Avenue 

Thompson Brick Co 


342 
342 
326 
326 



fl.AV KKSOrRCES AND CERAMIC INDISTRY 
INDEX TO CLAY SAMPLES. BY COUNTIES-^Contlnued 



351) 



County 


Name of property 


Designation of clay 


i 
p 


Description of 
property, 
page 

Class No 


H 

; 5 




Amer. Silica Co 


Death Valley superfine 


269 


10 




316 










Merrv Widow Mine 


Impure kaolin 


115 
116 
114 


17 

17 

9 


90 
90 
89 


349 




Titus . . 


Impure kaolin.. . 


349 




Titus 


312 










Lake 


Keiseyville _ . . . 


Common 


188 


14 


92 


336 










I.nR \nceles 


Da\i(ison Brick Co. 


Common 


60 
61 


15 
15 


100 
102 


340 




Gladding. McBean & Co 


Santa Monica common 


341 


Msrin 


McNear Brick Co. 


Shale _... 


198 


13 


124 


329 












Area. 


Common 


117 
214 


12 
12 


130 
131 


324 




Monterey Mission Tile Co 


Adobe 


327 










Clark and Marsh 


Kaolin, average- 


190 
191 
192 


1 
5 
5 


133 
133 
133 


261 






Kaolin, selected 


280 




Kaolin, lower tuimel 


281 








Nevada 


Banner Mt. Road 




170 
168 
172 
171 
159 
160 
166 
167 
169 
158 


10 

9 

15 

13 

1 

.1 

10 
9 


136 
136 
136 
136 
137 
137 
138 
138 
138 
138 


315 




Beascr Ranch 




313 






Pipe clay 


342 




North Bloomfield Rd 




329 




Pine Hill Mine 


Kiinlin 


261 




Sonntaff Ranch 


Kaolin . 


261 




Kaolin.. 


316 




Kaolin 


315 






313 




Sweet Ranch (Pine Hill) 


Kaolin 














Amreco fireclay 


266 

270 

268 

64 

63 

65 

221 

282 

223 

62 


6 
5 

1 
1 
1 

12 

12 

5 

15 

1 


140 
140 
140 
140 
140 
140 
141 
141 
142 
145 


292 




Brea C. P. Co. 


.\rc fireclay 


282 




1^1 Toro crude . 


260 




Hunter Ranch — lower 

Hunter Ranch— upper 

Common 


260 
260 
322 




Gladding, McBean & Co 

Vitrefrax Co. 


Goat Ranch flint 


330 




Goat Ranch flint 


282 




Goat Ranch shale M M 3 

O'Neill Ranch fireclay 


343 
259 








Placer 


Clay Corporation of Cal 

Gladding, McBean & Co 

Lincoln C. P. Co. 


Lincoln fireclay 


280 
152 
153 
156 
155 
157 
145 
146 
147 
148 
149 
150 
151 
165 
162 
163 
164 
161 
261 
262 
263 


8 
8 
7 
7 

12 
8 
6 
8 
8 

14 
7 
6 
8 

■"17" 

""\2 

17 

6 


147 
147 
147 
152 
152 
152 
156 
156 
156 
156 
156 
156 
156 
159 
159 
159 
159 
159 
159 
159 
159 


305 




Lincoln top clay 


304 






299 




Lincoln fire-proofing 


299 






325 




Lincoln terra cotta 


304 




No.O .- 


291 




M iacellancous 


No. 1-6 


303 




No. 7 


303 




No 8 


336 




No.9 


298 




No 10 


291 




Washed china clay 


303 




Alta 








Baxter 






Baxter . 


350 




Baxter 












Kaolin (impure) 


328 








350 




Kaolin (imoure) , 


292 








Pivprfltdp 


Alberhill C & C Co 


A-clay . 


14 

17 

18 

11 

12 

19 

9 

271 

272 

274 

10 

29 

13 

15 

27 


6 

5 

12 

1 

1 
9 
6 
7 
6 
7 
14 
2 
7 
2 
6 


169 
169 
169 
169 
169 
169 
169 
169 
169 
169 
169 
169 
169 
169 
169 


287 






Bone W-105 


277 




Clark tunnel mottled 

China E-101 


321 

257 




China E-102 


257 




Diamond 


311 




Hillblue 


287 




Hill blue, lower tunnel 

Hill blue, main tunnel 

Hill blue, upper tunnel 


301 
292 
302 
3.34 






264 




Main tunnel ex. select 

Ma.in tunnel select 


296 
264 




No. 10 


287 



360 



DIVISION OF MINES AND MINING 
INDEX TO CLAY SAMPLES. BY COUNTIES— Continued 



County 


Name of property 


Designation of clay 


CD 

B 

•3, 

p 


o 

»" 

CO 

p 


Description of 
property, 
page 


: ? 






Pink mottled.... 


7 
8 
21 
28 
273 
23 
16 
25 
24 
26 
22 


13 

12 

14 

2 

3 

5 

10 
9 
12 
12 
14 


169 
169 
169 
169 
169 
169 
169 
169 
169 
169 
169 


328 




Red No. 2 


321 




Sagger. 


334 




SH-3.. . 


264 




SH-4 


273 




West blue 


277 




West blue select 


314 




West tunnel blue 


311 




West tunnel mottled. 


321 




Westyellow.. . 


321 




Yellow Owl Cut... 


335 










Emsco Clay Co. (Harrington pit) 


Bone. -. 


73 
71 
72 
69 
70 


12 

5 

13 

12 

3 


171 
171 
171 
171 
171 


323 




Pink mottled 


278 




Red. 


328 




Red Horse... . 


323 




White (No. 5) 


272 










Gladding, McBean & Co. (Alber- 
hillpitB) 


Bone (W-105?) 


98 

90 

93 

91 

92 

96 

103 

104 

105 

102 

101 

97 

99 

94 

95 

100 


3 

2 

2 
1 
6 
3 
1 
5 

12 
6 
7 
6 
9 
9 
9 

12 


173 
173 
173 
173 
173 
173 
173 
173 
173 
173 
173 
173 
173 
173 
173 
173 


272 






Main tunnel.. 


265 




Main tunnelselect 


265 




Main tunnel sand 


260 




Main tunnel yellow.. . . 


289 




No. 10 


272 




Sloan, bone . 


260 




Sloan, No. 5 


279 




Sloan, red.. . 


324 




Sloan, sand . 


290 




Sloan, white 


298 




Smooth bunker 


290 




Tile.... 


312 




West blue 


311 




West blueselect 


311 




Yellow stripping 


323 










Hudson Ranch- 


Clay. .. 


89 
88 


15 
10 




341 






Sand 


315 










Los Angeles Brick Co 


Bone, high-alumina 


231 
87 

232 
82 

229 

230 
78 
77 
76 
81 
86 
85 
84 
83 
75 
74 
79 
80 


5 
5 
5 
10 
7 
7 
6 
5 

t 
5 

7 
6 
7 
14 
5 
5 
7 


175 
175 
175 
175 
175 
175 
175 
175 
175 
175 
175 
175 
175 
175 
175 
175 
175 
175 


281 






Bone, smooth 

Bone. smooth . 


279 
281 




Clay shale . 


315 




No. 7 


300 




No.9 


300 




No. 10 


288 




No. 20 


278 




.No. 23 


288 




No. 25 


289 




No. 26 bone 


279 




Pink mottled 


298 




P. M. fireclay 


289 




Red 


297 




Red No. 2 


335 




West bone 


278 




West pit fireclay 


278 




West pit mottled ... 


297 










Pacific C. P. Co. (Alberhill and 
Corona pits) 


Douglas . 


110 
111 
109 
108 
112 
113 
67 
66 


7 

10 
2 
6 
12 
12 
5 
5 


176 
176 
176 
176 
178 
178 
179 
179 


298 






Douglas lower 


315 




Douglas main tunnel 

Douglas upper. . 


266 
290 




Hoist pit blue ... 


324 




Hoist pit red. 


324 




McKnight fireclay. 


277 




McKnight sewer pipe 


277 




Temeseal Water Co 


Pink mottled . . 


218 
42 
43 


13 
15 
15 


181 
181 
181 


329 




Wilson, J. W 


Common.. . . 


340 






Common 


340 








Sacramento 


Michigan Bar. . 


Cutter 


143 
144 

210 
212 


4 

3 

14 

14 


185 
185 
186 
186 


274 




Natoma Clay Co 


Van Vleck.. 


273 




No. 1 . 


337 






No.3 


337 



CLAV RHSOIHCES AM) CERAMIC IXIHSTHV 
INDEX TO CLAY SAMPLES. BY COUNTIES— Continued 



861 



County 


Name of property 


Designation of clay 


■2. 
p 


Q 

p 


Description of 
property, 
page 


; f 




Paicincs 


Common 


118 


15 


192 


341 














Hart kaolin 


57 
55 
46 
53 
44 
45 


2 

10 

17 

6 

2 

2 


194 
195 
195 
196 
196 
196 


264 




Gladding, McBean & Co 


Bryman clay _ .. 


314 




Impure kaolin 


349 




Millet & Kennedy .. 


Buff-burning 

Pacific kaolin (Hart) 


288 




Standard San. Mfg. Co. 


264 






Pacific kaolin (Hart) 


264 








San Dieffo 


California C. P. Co 


Cardiff fireclay 


36 
38 
37 
35 
41 
39 
40 
30 
31 
33 
34 
32 


9 

1 

1 

12 

17 

7 

12 

15 

15 

6 

6 

12 


201 
201 
201 
202 
202 
203 
203 
203 
204 
205 
205 
205 


311 




ElCajonMt 


Kaolin, ayeragc 


259 




Gladding. McBean & Co 

Morris.H. T 


Kaolin, selected.. . 


259 




Cardiff 


322 




Common 


348 




Pacific C. P. Co. 


Kelley Ranch white 


296 




San Diego T. & B. Co... 


Kelley Ranch yellow 


322 




Rose Canyon .. 


339 






Rose Canyon 


340 




Vitrified Products Co. 


Cardiff fireclay 


287 






Cardiff fireclay. 


287 




Linda Vista shale 


322 








San Luis Obispo 


Santa Margarita 


Shale 


216 
217 


12 
12 


215 
215 


327 




Shale 


327 








S:\nt.a Barbara 


Brentner 


Carpinteria 


3 
1 

2 


17 
15 
15 


218 
218 
218 


.348 




Muegenberg& Whitiker. .- 


Santa Barbara 


338 




Toro Canyon . 


338 










Beltane.- . 


Buff -burning 


197 
194 
195 


6 

1 
1 


227 
228 
228 


291 




Weiss J. H. 


Average white . 


262 






Selected white.. ,. 


262 










Cummings Ranch 


Shale 


205 


17 


229 


349 








Tulare 


Sears W. A. - 


Kaolin (impure) 

Kaolin (impure) 


283-A 
283-B 
284 
285 


9 
9 

10 
5 


232 

232 

232 

. 232